Trouble starting...

[magicmonkey]

ok, so I got a new battery over the weekend and charged it up for 24 hours before putting it on the bike. Now it's on there and on Sunday the engine just popped into life when I pressed the starter. However, the maiden voyage got postponed because I had a horrible hangover so I went and had a couple of beers instead ;)

so last night I went to turn the engine over and it just didn't want to pick up, turns over fine, sounds like it's about to start but doesn't actually pick up. I'm sure it would if I kept on trying for ages as that's what it would do with the old battery but I'd really like to fix the problem rather than wear out a brand new battery for no good reason. Work I've done on the engine is pretty much just on the carbs but they're all sparkly clean now and shouldn't be the problem (when I did have the bike started and warm last time it was quite happy to sit at idle and rev how it was meant to with no choke on etc.). I'm starting the bike with the petrol set to 'prime' and the choke full on with no throttle as this seems to be how it prefers to start. Anyone got any ideas of things I should look at? I'm starting to scratch me head far too much now!

[bogan]

was it running after you cleaned the carbs, or is this the first time youve tried to start it. As carbs are tempremental beasties who have to be tuned properly as well as being clean!

[magicmonkey]

Yeah, it's been ticking over quite happily since the carbs have been cleaned, it's just the starting of the engine which is causing issues at the moment

[bogan]

maybe some bad fuel at the bottom of the tank got sucked through while its been on prime, also try differnt combinations of choke and throttle when you start it.

[T.W.R]

Only use prime if it's been sitting for a while without running.......you had it running Sunday so now having used the prime position you've probably flooded it

[bogan]

Only use prime if it's been sitting for a while without running.......you had it running Sunday so now having used the prime position you've probably flooded it

good point, float valves don't generally seal properly so that probly all it is.

[magicmonkey]

sounds like a good point. I'll pull the plugs out when I get home and let the engine air out for a bit before I try and start it agin :)

[magicmonkey]

Actually, on thinking about it a bit more, I had this problem before I was starting with the petrol set to prime so I'm not 100% this is going to work. I'll certainly try it but any other ideas would be very welcome too!

[bogan]

dont worry bout pulling the plugs out, tis the carby that will be flooded, excess fuel in the cylinder will clear out when the engine turns over (may take a few turns though), just drain the carb, some have screws near the bottom with a hose and other just have a bolt you take out, if its the latter rags and plastic sheet 'funnel' into waste container is the way to go.

[magicmonkey]

dont worry bout pulling the plugs out, tis the carby that will be flooded, excess fuel in the cylinder will clear out when the engine turns over (may take a few turns though), just drain the carb, some have screws near the bottom with a hose and other just have a bolt you take out, if its the latter rags and plastic sheet 'funnel' into waste container is the way to go.

another good point! Would probably account for the problem as well! Shame really as this means I have to get the petrol tank and the airbox off to get at the drain screws, doh!

[bogan]

another good point! Would probably account for the problem as well! Shame really as this means I have to get the petrol tank and the airbox off to get at the drain screws, doh!

really? this on your gn or zxr?, wouldnt have though either needed the tank and airbox off to get at the drian screw

[magicmonkey]

it's on the ZXR. I could probably get to the carb screws without removing anything but they need a star drive and the only one I have that will fit is on a short and wide screwdriver so it's more about that than the design of the bike itself. I'll have a close look at it this afternoon but I'm pretty sure that's how it'll go ...

*edit*
I'm pretty good at getting these off now anyway, will only add 5 minutes to the job :)

[bogan]

ahhh, fair enuf, spose the zxr has quad carbs as welll, have fun with that :niceone:

[magicmonkey]

ahhh, fair enuf, spose the zxr has quad carbs as welll, have fun with that :niceone:

heh, fun indeed! Still, if I can work out how to get the thing to start up nicely then I'll be well chuffed as that'll be pretty much the end of the engine side of the project. After that it'll all be about cleaning and paint which is going to be pretty boring but should be rewarding once it's done :D

[Grasshopperus]

Hey mate, I've recently had the exact same problem with my ZXR.

First, although you've cleaned the carbs the real check is to make sure gas really is getting into the cylinders; can you smell gas after trying to start it for a while? You might need to sniff the exhaust to check that.

I took the spark plugs out one-by-one and verified they had a strong spark. In my case, 2 of the spark plugs had a barely visible spark whilst the other two had a bright, fat spark.

ZXRs have two ignition coils (ICs), each powering two sparkplugs. In my case, the two weak sparkplugs were connected to the same IC meaning it was an IC problem.

I took all the leads off both ICs, removed them and inspected. What I found was that the bad IC was heavily corroded where the sparkplug leads connect (it's just got a spike that you impale the leads onto). The leads were also corroded.

So, I cut the sparkplug leads a little shorter, sprayed heaps of CRC into the IC and cleaned it up using a needle file (a bit of stiff wire would've worked too). While I had the ICs out I jammed a multimeter onto both the primary and secondary coils and verified that the resistance was within what the factory say it should be.

Put it all back together, verified that all the sparkplugs now had a good spark. Tried to start bike and yay, it's all good now.

You owe me green bling if that's what's wrong monkeyman.

[magicmonkey]

Hey mate, I've recently had the exact same problem with my ZXR.

First, although you've cleaned the carbs the real check is to make sure gas really is getting into the cylinders; can you smell gas after trying to start it for a while? You might need to sniff the exhaust to check that.

I took the spark plugs out one-by-one and verified they had a strong spark. In my case, 2 of the spark plugs had a barely visible spark whilst the other two had a bright, fat spark.

ZXRs have two ignition coils (ICs), each powering two sparkplugs. In my case, the two weak sparkplugs were connected to the same IC meaning it was an IC problem.

I took all the leads off both ICs, removed them and inspected. What I found was that the bad IC was heavily corroded where the sparkplug leads connect (it's just got a spike that you impale the leads onto). The leads were also corroded.

So, I cut the sparkplug leads a little shorter, sprayed heaps of CRC into the IC and cleaned it up using a needle file (a bit of stiff wire would've worked too). While I had the ICs out I jammed a multimeter onto both the primary and secondary coils and verified that the resistance was within what the factory say it should be.

Put it all back together, verified that all the sparkplugs now had a good spark. Tried to start bike and yay, it's all good now.

You owe me green bling if that's what's wrong monkeyman.

believe it or not, I've already had the IC's off, cleaned them up and sprayed CRC in the right holes. Still, if I'm going to get the tank and the carbs off tonight anyway I might as well spend the extra 10 minutes checking those as well, just to be sure!

ps. have some green bling anyway :)

[Grasshopperus]

believe it or not, I've already had the IC's off, cleaned them up and sprayed CRC in the right holes. Still, if I'm going to get the tank and the carbs off tonight anyway I might as well spend the extra 10 minutes checking those as well, just to be sure!

ps. have some green bling anyway :)

Ah cool.

Well, visually check the spark, check IC resistance, and then make sure you've got the right sparkplug leads attached into the right IC holes anyway.

Good luck.

[centaurus]

ok, so I got a new battery over the weekend and charged it up for 24 hours before putting it on the bike. Now it's on there and on Sunday the engine just popped into life when I pressed the starter. However, the maiden voyage got postponed because I had a horrible hangover so I went and had a couple of beers instead ;)

so last night I went to turn the engine over and it just didn't want to pick up, turns over fine, sounds like it's about to start but doesn't actually pick up. I'm sure it would if I kept on trying for ages as that's what it would do with the old battery but I'd really like to fix the problem rather than wear out a brand new battery for no good reason. Work I've done on the engine is pretty much just on the carbs but they're all sparkly clean now and shouldn't be the problem (when I did have the bike started and warm last time it was quite happy to sit at idle and rev how it was meant to with no choke on etc.). I'm starting the bike with the petrol set to 'prime' and the choke full on with no throttle as this seems to be how it prefers to start. Anyone got any ideas of things I should look at? I'm starting to scratch me head far too much now!

On my '99 ZX6r I discovered that if I blip the throttle and kill the engine before it comes back to idle, next time it starts much faster. It's true, I have the baffle removed from the stock can so it might be that at idle the engine ss a bit lean, but for me it seems to do the trick. If I don't blip the throttle before stopping the engine, it takes a few turns before the engine comes to life.

[CookMySock]

If it's flooded, leave it for an hour, and choke off and go full-throttle and start it. It should pick up and start. Don't move the throttle - just hold it hard against its' full-open stop and wind the engine over. Watch out when it starts - you don't want to hit 19,000rpm.

Steve

[magicmonkey]

Ah cool.

Well, visually check the spark, check IC resistance, and then make sure you've got the right sparkplug leads attached into the right IC holes anyway.

Good luck.

I think it might be a good idea for me to clean the plugs as well, either that or just buy new ones (although they're bloody expensive!!)

[magicmonkey]

Ah cool.

Well, visually check the spark, check IC resistance, and then make sure you've got the right sparkplug leads attached into the right IC holes anyway.

Good luck.

well, looks like you were right on the button there mate! I trimmed down the IC end of the leads a little as there was no actual wire showing and popped them back on with some CRC down the holes and now I have spark like this:

1 - weak
2 - none
3 - strong
4 - weak

I'll go over it with a multimeter later tonight (pizza turned up while I was half way through and I lost interest!) but what I think has happened is that the lead for 2 needs a little more attention or maybe the spike needs cleaning and the IC for 1 and 4 either needs a damned good clean or just replacing (which I'm hoping isn't the case as they'll probably be expensive!).

Anyways, thanks for the pointer there, before I'd just checked that there was spark in each cylinder rather than checking the actual quality of the spark. Now I know where the problem is I can get it fixed and take it out for a spin :D

[magicmonkey]

well, I've made sure that the sparks can all jump a decent distance to the block, cleaned the coils, trimmed the leads and cleaned the plugs. I'm as sure as I can be that the spark side of things is ok...

While I had the airbox off I decided to replace the o-rings on the vacum and fuel parts of the carbs as a few of them had come into contact with carb cleaner and were starting to perish (I live and learn!) now the damned thing is even further from starting, just turns over as if there's no fuel getting to the cylinders so I'm not too chuffed with my work over the last coupld of days! I'm going to have a smoke then drain the carbs to see how far the fuel is getting and hopefully there won't be any in there (I put a fuel filter in as well, am hoping it's causing a blockage so I can just take it out of the loop)

Any other handy hints are gratefully received at the moment!!!

[Grasshopperus]

now I have spark like this:

1 - weak
2 - none
3 - strong
4 - weak


There's a problem right there. Mine wasn't starting with strong-weak-weak-strong and yours is far worse.

No spark on cylinder #2? Try getting the known good spark plug from #3 and trying it on all the other leads. That'll tell you if you have bad sparkplugs or bad ignition system in general.

[magicmonkey]

There's a problem right there. Mine wasn't starting with strong-weak-weak-strong and yours is far worse.

No spark on cylinder #2? Try getting the known good spark plug from #3 and trying it on all the other leads. That'll tell you if you have bad sparkplugs or bad ignition system in general.

Yup, been down that road this morning and now I've got a decent spark on every cylinder (mainly thanks to your hints about cleaning the coils, so thanks for that :))

At the moment I'm pretty much where I was at the beginning of the week, I can start her up but it takes a lot of cranking over to do. It's intermittent as well so sometimes it'll just fire straight into life how it should do and sometimes it'll just refuse to do anything. I know the spark and the petrol are getting there so I'm starting to have compression worries, might just pick up a compression tester over the weekend if they're not too expensive ...

[Grasshopperus]

So it's still a pain to start eh. I've got a bunch of questsions

1. When it finally does start does will it idle?
2. When it finally does start will it rev-up without hesitation?
3. After running it for a bit turn it off, wait 5 seconds, and then try to start it up again. Does it start easily now?
4. Does it blow smoke after starting? What color?
5. When it's trying to start is it catching at all?
6. Have you inspected the choke mechanism on the carbs? Are all the choke valves opening?
7. Have you changed the oil on the bike since you got it?
8. Has it ever started easily since you got the bike?

[magicmonkey]

1. When it finally does start does will it idle?

yup, idles fine when warm, I had it ticking over around 2k quite happily

2. When it finally does start will it rev-up without hesitation?

yup, althought the accelerator bogs down the engine in the first few second someitmes it's always fine after that (I think that's more to do with my work than anything else, have messed around with the throttle cables a bit and not sorted them out yet)

3. After running it for a bit turn it off, wait 5 seconds, and then try to start it up again. Does it start easily now?

nope, that's the bit that's really confused me, I'd expect it to start better when warm but no joy on that one

4. Does it blow smoke after starting? What color?

there was some white smoke when it started the first time which lasted about 2 minutes but it's ben fine since then with no smoke at all. I just put that down to the engine being sat around for 2 years

5. When it's trying to start is it catching at all?

yup, it'll catch but not fire up

6. Have you inspected the choke mechanism on the carbs? Are all the choke valves opening?

yeah, chokes can be seen opening and the engine responds to the choke so I'm sure they're working inside and out

7. Have you changed the oil on the bike since you got it?

Nope, it's on the list to do before the first ride, you think that'd help or are you thinking about looking for silvery nastiness in there?

8. Has it ever started easily since you got the bike?

yeah, a couple of times, no idea why though!

[magicmonkey]

well, I decided to check the coils again this morning, just to make sure, and found that th eleads weren't going into the coils far enough and any connection made that end would have had to arc. so, Iwent to bare some more wire and completely cocked it up, took all the insulation with it, doh!!!

Popped into the local bike guy to pick up some more leads and he tells me that the leads I have are the wrong type and sells me the right wire to do up the lot of them for $10, awesome! So, now I've spent some time making up the leads and checking spark and it's much better, like, one hell of a lot better!

still not starting easily though, doh!!!

[Paul in NZ]

Eventually you will need to baseline all the adjustments on this thing which will include valve clearances and timing but I'd really recommend a leakdown test as well. That will tell you if the valves or rings are leaking.

Keep at it - you will get there

[Grasshopperus]

Hmm, nothing seems obviously wrong to me there (I'm a noob mechanic though).

Do change the oil and though, doesn't have to be the best oil, just get some new stuff in it. You may find that the current oil is so gunged up that it's actually providing too much resistance to start the engine (just guessing, I'm not sure if old oil can have that effect or not)

generic 20w-40 car oil and a "HiFlo" HF-303 oil filter is what I'm using on my zxr at the mo.

I find that as my bike is catching I have to lightly play with the throttle a bit to make it fire into life. However, that's only required for the first start of the morning when it's cold. After that it starts fine in about 1 second.

I think your problem must be electrical;

you're obviously getting gas (it idles and revs up no probs)
you've got compression (revving up)

Do you have a multimeter? It may be a bad battery. Test the batteries resting voltage with bike off, and then with ignition on, and then after starting it too (verify charging system is working)

Also, the next time you take your carbs apart make sure that the main jets are the correct factory size, #122 for cylinders 1 and 4, #125 for cylinders 2 and 3. Getting the sizes right is what fixed all my engine rev-up hesitation problems.

Someone has obviously tried to do some mods or something to your bike (like the spark plug leads) so you probably don't know what else they've tried to do.

Lastly with the choke, I guess you've tried varying the position of the lever, full choke floods mine so I play somewhere between 50-80% choke just 'searching' for the right setting.

[magicmonkey]

welll, I had a huge backfire yesterday when I tried to start it, sounded like a gun! Seeing as I'd just played around with the electrics I thought I'd probably wired it up wrong and it was firing with the exhaust valves open but I went back with the manual and checked everything over and it's fine. At the moment it just doesn't want to catch, no hint of starting up at all. I'm going to take the morning off as I've spent far too much time in the garage the last few days! I'm going to get on the GN and head over the rimutakas after I've had some breakfast, maybe come back to this later today as I'm just pissed off with it at the moment. In the meantime, and hints gratefully received!!

[magicmonkey]

Hmm, nothing seems obviously wrong to me there (I'm a noob mechanic though).

Do change the oil and though, doesn't have to be the best oil, just get some new stuff in it. You may find that the current oil is so gunged up that it's actually providing too much resistance to start the engine (just guessing, I'm not sure if old oil can have that effect or not)

generic 20w-40 car oil and a "HiFlo" HF-303 oil filter is what I'm using on my zxr at the mo.

I'm not so sure that an oil change would fix a starting problem, I'd assume that if it was that gunked up it wouldn't just dribble out the drain but I could well be wrong, I'm also a complete noob mechanic (in-case you hadn't noticed!)


I find that as my bike is catching I have to lightly play with the throttle a bit to make it fire into life. However, that's only required for the first start of the morning when it's cold. After that it starts fine in about 1 second.

yeah, mine seems to like the tiniest amount of play at the closed end of the throttle and then a small rev as it's catching


I think your problem must be electrical;

you're obviously getting gas (it idles and revs up no probs)
you've got compression (revving up)

I think I've got an electrics problem for sure, what I'm really worried about is the problems I'll find when I've fixed that!


Do you have a multimeter? It may be a bad battery. Test the batteries resting voltage with bike off, and then with ignition on, and then after starting it too (verify charging system is working)

Yup, the battery which came with the bike was on it's last legs so there's a new one in there at the moment, it's fully charged and the charging system is definitely working (I love multimeters, got to be one of the most useful tools ever made!)


Also, the next time you take your carbs apart make sure that the main jets are the correct factory size, #122 for cylinders 1 and 4, #125 for cylinders 2 and 3. Getting the sizes right is what fixed all my engine rev-up hesitation problems.

well, that's going on the to do list :)


Someone has obviously tried to do some mods or something to your bike (like the spark plug leads) so you probably don't know what else they've tried to do.

yeah, I get the impression they knew fuck all about bikes and had an over inflated sense of their own mad mechanic skillz! The wrong kind of leads is just a complete idiot mistake and shows that whoever it was didn't bother talking to anyone who knew what they were doing or read a manual, makes me worried :S


Lastly with the choke, I guess you've tried varying the position of the lever, full choke floods mine so I play somewhere between 50-80% choke just 'searching' for the right setting.

good point, I am starting with 100% choke at the moment, I'll bring that down some and see how that goes...

[T.W.R]

What's the air gap between the pulser coil & the timing rotor like???

[magicmonkey]

What's the air gap between the pulser coil & the timing rotor like???

the what between the what and the what?????

I'll have a peek at the manual in a bit!

[MSTRS]

generic 20w-40 car oil and a "HiFlo" HF-303 oil filter is what I'm using on my zxr at the mo.


Bad boy. Get bike-specific oil in there. Mineral or semi-synthetic...4T for sportsbikes is the one you want.

[T.W.R]

the what between the what and the what?????

I'll have a peek at the manual in a bit!

exciter coil & timing rotor (under the cover righthand side of the engine) it's the magic wee article that sends the important pulses to the coils.
the air gap is clearance between the coil and the timing rotor........don't bother trying to measure it with a feeler gauge as it's a curved surface (if you do you'll get a incorrect measurement) best is a piece of paper folded in two (it only needs a small gap...not touching nor a large gap)

[magicmonkey]

exciter coil & timing rotor (under the cover righthand side of the engine) it's the magic wee article that sends the important pulses to the coils.
the air gap is clearance between the coil and the timing rotor........don't bother trying to measure it with a feeler gauge as it's a curved surface (if you do you'll get a incorrect measurement) best is a piece of paper folded in two (it only needs a small gap...not touching nor a large gap)

ok, I get you now, I've always called the pulser the 'pickup', hence the confusion. I think I'm going to hold off on that though as itwas working before and now it's not, the problem seems to lie with something I've actually done rather than something else at the moment.

It seems that the engine now wants to backfire and not catch immediately after I've sorted out the spark plug leads. Considering that the spark was really weak but still fired up I'm beginning to wonder if the air/fuel ratio was adjusted for the weak spark and the decent spark is having trouble igniting it. I can't quite work out how that would be the problem (too lean, too rich etc) or even how the air/fuel ratio would allow it to ignite with a weak spark but not a strong one. I'm thinking that some playing with the pilot screws might be in order but if anyone has a better suggestion I''d be very happy to try it out!

I might also get the engine cover off and just line up the timing markings to make sure that it hasn't been advanced by the previous guy (apparently that's a common mod on these to get more out of the mid-range) ...

[T.W.R]

pulser/exciter/pick-up all the same just depends on where you've worked & who you've worked with...just slang terms for the same thing.

Just odd that you've had it running prior to all this diddling around and now it's playing up ???
2000rpm idle you mentioned in a previous post doesn't sound right though even if these wee sewing machine engines rev like buggery...1500rpm I'd consider a high idle.

Pilot air screws hardly get fiddled with but if you do adjust them remember the setting is taken from a soft bed not firmly wound in.....they have a small rubber O-ring that does harden quite significantly and can alter the prescribed setting a lot.

[magicmonkey]

pulser/exciter/pick-up all the same just depends on where you've worked & who you've worked with...just slang terms for the same thing.

Just odd that you've had it running prior to all this diddling around and now it's playing up ???

yeah i know, it seems that something I've done has cocked it up and I'm completely in the dark about what that is. It worked fine after I did the carbs and I only improved the spark so I can't see where one of those things has screwed it up. Still, these are the joys of a beginner mechanic with a broken toy I suppose :p


2000rpm idle you mentioned in a previous post doesn't sound right though even if these wee sewing machine engines rev like buggery...1500rpm I'd consider a high idle.

well, it seems other zxr owners think that about 1500 is normal and I probably could have dropped the idle speed to around there but I was worried about stalling when it was so bloody hard to get started again, hence all of this messing around! I'll probably revise the 2000rpm figure once I've got the starting issue sorted ...


Pilot air screws hardly get fiddled with but if you do adjust them remember the setting is taken from a soft bed not firmly wound in.....they have a small rubber O-ring that does harden quite significantly and can alter the prescribed setting a lot.

I'm beginning to think that playing with the pilot screws is probably a bad idea, I just can't see how they'd fix the problem I'm having considering that I haven't touched them so far and the problem didn't exist a couple of days ago.

I've decided to have a day away from the bike today as it's just pissing me off at the moment and I'm bound to do something silly if I'm wound up with it. I've decided that beer and sun can come before the bike just for one day ;) tomorrow night I'll go back over everything I've done and check it against the manual, hopefully I'll find something really stupid that I've done!

[magicmonkey]

ok, now I'm completely stumped!! I've checked spark to each cylinder and that's fine, I've triple checked the wiring and they're all firing in the right order, I've had the carbs off again and put them back together with the manual and checked everything there. So there's spark to each cylinder, there's fuel getting in there (I can smell it from the exhaust) but it just refuses to kick into life, not even the slightest hint of one cylinder firing. I'm sure it's something to do with the work I've done, which is all spark and carbs, but I've checked them over thoroughly and I still can't get life out of the damned thing! Any ideas are gratefully received at this point!

[CookMySock]

Halve the spark plug gap - that'll make it not quite so sensitive. Trailer it up the top of a really big hill, stick it third gear and ride it all the way down.. fiddle with choke and throttle. You should be able to get at least one backfire outa it.

Steve

[magicmonkey]

Halve the spark plug gap - that'll make it not quite so sensitive. Trailer it up the top of a really big hill, stick it third gear and ride it all the way down.. fiddle with choke and throttle. You should be able to get at least one backfire outa it.

Steve

lol, I thought the mechanicas forum wasn't for messing around in :p

[MSTRS]

You haven't done something silly like flicked off the killswitch?
It happens - DAMHIK

[magicmonkey]

nah, the kill switch is off, the engine does get turned over by the starter, just doesn't actually sping into life

[CookMySock]

lol, I thought the mechanicas forum wasn't for messing around in :pLOL you think I am joking. :laugh:

Steve

[MSTRS]

nah, the kill switch is off, the engine does get turned over by the starter, just doesn't actually sping into life

OK.
We all know an engine needs 3 things to go...but each must be present in the right quantities/time etc. The higher performance an engine is, the more critical those factors.You prolly need an 'expert' there with the bike. And maybe, some starting rollers like a few of the racers use...

[jim.cox]

ok, now I'm completely stumped!! I've checked spark to each cylinder and that's fine, I've triple checked the wiring and they're all firing in the right order, I've had the carbs off again and put them back together with the manual and checked everything there. So there's spark to each cylinder, there's fuel getting in there (I can smell it from the exhaust) but it just refuses to kick into life, not even the slightest hint of one cylinder firing. I'm sure it's something to do with the work I've done, which is all spark and carbs, but I've checked them over thoroughly and I still can't get life out of the damned thing! Any ideas are gratefully received at this point!

Spark has to occur at the right time - check the timing - I've seen motors set up 180 degress out :(

[magicmonkey]

Spark has to occur at the right time - check the timing - I've seen motors set up 180 degress out :(

yup, I have thought about looking at the timing but I'm a bit weary of that as it would work fine before I played around with the carbs and spark, I know it's not out far enough to actually prevent it from firing ...

[magicmonkey]

OK.
We all know an engine needs 3 things to go...but each must be present in the right quantities/time etc. The higher performance an engine is, the more critical those factors.You prolly need an 'expert' there with the bike. And maybe, some starting rollers like a few of the racers use...

yup, I get what your saying, I'm just completely stumped as it seems that everything is where it should be. I di wonder if maybe one of the vacum lines is blocked or something, would that be able to cause this problem?

[Grasshopperus]

OK, I'm out of ideas too.

Crash start it. Ride the shit out of it for 30 mins, red line once per minute, show it who's boss. That'll learn it.

[magicmonkey]

OK, I'm out of ideas too.

Crash start it. Ride the shit out of it for 30 mins, red line once per minute, show it who's boss. That'll learn it.

lol, at the moment I'm seriously considering doing something like that, only thing stopping me is that I haven't got a trailer of a tow bar to get it back up the hill :p

[T.W.R]

When you say you've got spark to all cylinders is it a good spark ie: pale blue or a pissy yellow spark?
going back over some of your earlier posts about what had happened and what you had encountered I'd be inclined to think you've got too much fuel getting to the cylinders ie: drowning the spark.

A good spark should be able to jump a 8mm gap on a tester

[magicmonkey]

When you say you've got spark to all cylinders is it a good spark ie: pale blue or a pissy yellow spark?
going back over some of your earlier posts about what had happened and what you had encountered I'd be inclined to think you've got too much fuel getting to the cylinders ie: drowning the spark.

A good spark should be able to jump a 8mm gap on a tester

The spark was pissy and weak, now it's a nice strong one and can jump about a 1cm gap to the engine block (approximated by eye, hardly scientific but I'm fairly confident in it)

I am wondering af there might be petrol that's refusing to come out of the cylinders for some reason but I can't see the plugs being wet at all when I pop them out. I'll get those plugs out again and double check later tonight though.

[T.W.R]

another thought is the electrolisis cleaning bent you went on with the carbs...when you finished doing that did you actually thoroughly clean the carbs out afterwards??? doing that does leave a scale type deposit in confined spaces and if you hadn't removed the emulsion tubes etc you're bound to have blocked galleries with the carbs & possibly partially blocked primary & main jets.
it's always easier & safer to just clean carbs with actual fuel rather than foriegn materials especially water as foriegn materials contribute to the majority of carb problems

[MSTRS]

... but I can't see the plugs being wet at all when I pop them out....

There's a clue. Got the tank tap set to prime?

[magicmonkey]

another thought is the electrolisis cleaning bent you went on with the carbs...when you finished doing that did you actually thoroughly clean the carbs out afterwards??? doing that does leave a scale type deposit in confined spaces and if you hadn't removed the emulsion tubes etc you're bound to have blocked galleries with the carbs & possibly partially blocked primary & main jets.
it's always easier & safer to just clean carbs with actual fuel rather than foriegn materials especially water as foriegn materials contribute to the majority of carb problems

I did make sure to remove everything I could from the carbs (including the jets but excluding the pilot screws) and gave them a good scrub down with carb cleaner and a toothbrush when they came out, it's also been running since I did that. I must confess I've been thinking about trying to source another set of carbs if I can get them for a reasonable price though as I do wonder if the amount of work I've done on them has blinded me to any glaring problems ...

[magicmonkey]

There's a clue. Got the tank tap set to prime?

I've drained the carbs that much recently that I have a routine in place at the moment! I usually out the tank on prime when I put it back on the bike, go and have a smoke and then pop it onto 'on' although I have played around with the positions to see if they help starting at all (also played around with having the tank cap open when starting to eliminate a blockage in the vacum tube)

[magicmonkey]

last night I just popped the spark plugs out and i've left them on the bench so that any fuel in the cylinders can evaporate, later tonight I'm going to check the float levels and then put a squirt of 'start ya bastard' into the cylinders before putting the plugs back in. Hopefully I'll get a vroom out of the engine and that'll just confirm that the spark is working properly. Then I can focus all my attention on the carbs, joy!

[The Pastor]

I think you might just have to call a mech aye

[bogan]

don't call a mech, you've come this far! have you checked the compression on each cylinder?

[magicmonkey]

I'm hoping to sort it out myself, I know it's just a pissy little problem but the kind of thing that will cost hundreds in labour for a mech to sort out (they won'tknow exactly what work I've done so they'll have to diagnose it from scratch).

I haven't checked the compression beyond making sure the rear wheel locks in first although getting a compression tester is on the cards if I can't get it running pretty soon as I've checked just about everything so far ...

[T.W.R]

have you tried pouring a small ( very small ) amount of oil into each cylinder then attempting to start the bike?

[magicmonkey]

have you tried pouring a small ( very small ) amount of oil into each cylinder then attempting to start the bike?

oil?? Really, what would that do?

[T.W.R]

oil?? Really, what would that do?

If the cylinders are down on compression via the rings the oil will temporarlily boost the compression ie: act as a seal on the top ring

[CookMySock]

Big hill time - someone will help you with it - tomorrow's saturday! You might have to shout them a pie for the use of their van/trailer.

No choke, select a gear so you get about 2-3,000 rpm, ignition on, and roll off down the hill. Just try small throttle openings. Don't forget helmet and gloves.

If you can't even make it backfire out the zorst, then you know it's time to stop punishing the starter and look elsewhere for the problem. Compression check, static timing, valve clearances etc.

Steve

[magicmonkey]

If the cylinders are down on compression via the rings the oil will temporarlily boost the compression ie: act as a seal on the top ring

ah ok, that make sense. That'll go on the list of things to do this weekend (which seems to be growing rapidly!)

[magicmonkey]

Big hill time - someone will help you with it - tomorrow's saturday! You might have to shout them a pie for the use of their van/trailer.

No choke, select a gear so you get about 2-3,000 rpm, ignition on, and roll off down the hill. Just try small throttle openings. Don't forget helmet and gloves.

If you can't even make it backfire out the zorst, then you know it's time to stop punishing the starter and look elsewhere for the problem. Compression check, static timing, valve clearances etc.

Steve

Thing is, I want to get the starting sorted, not just make the engine run (I know it'll run fine already) so bump starting it isn't going to do anything to fix the fault or narrow it down, unless I'm missing something off course and that's always a likelyhood!

[CookMySock]

Thing is, I want to get the starting sorted, not just make the engine run (I know it'll run fine already) so bump starting it isn't going to do anything to fix the fault or narrow it down, unless I'm missing something off course and that's always a likelyhood!Yeah it is odd it doesn't just "go".

The hill thing is just to discover if its you, or it. If it goes, it's you. If it doesn't, its it. ;)

And then you have your straight answer.

Steve

[T.W.R]

:shutup: if you're going to bump start the bike: select 2nd gear, let the clutch out & roll the bike backwards till it takes up compression, pull the clutch in and start pushing, drop the clutch and have a bit of throttle and it'll fire up within 3bike lengths.

None of this down hill bollocks cause if it does fireup with a bang things can get messy if you aren't quick enough to clutch it, break & keep it running.

[bogan]

how easy/hard does it turn over, same as usual? and do you smell un burnt gas when its been turning over for a while, sounds like its probly mechanically ok, spark is ok, but not sure bout fuel. I'm assuming you haven't touched the timing chain or ignition advance.

EDIT, hang on, are you sure it runs fine when crash starting it, but just not good when electric starting it?

[magicmonkey]

how easy/hard does it turn over, same as usual? and do you smell un burnt gas when its been turning over for a while, sounds like its probly mechanically ok, spark is ok, but not sure bout fuel. I'm assuming you haven't touched the timing chain or ignition advance.

EDIT, hang on, are you sure it runs fine when crash starting it, but just not good when electric starting it?

I haven't crash started it, I do know that the engine is happy to idle though. I'm holding off on the crash starting idea fro the moment as I can't see it testing anything that I've touched but I might head onto that and crash start to get the engine warm (if it works that is :s)

[CookMySock]

None of this down hill bollocks cause if it does fireup with a bang things can get messy if you aren't quick enough to clutch it, break & keep it running.It's only a little 250 inline four mate. If it kicks into life you leave the clutch out and let it have its' little purr and fart until it makes up its' mind.

Different story if it was a 2000cc vtwin with a supercharger on it - then you would want to watch it alright.

Steve

[T.W.R]

:rolleyes:
I've seen 80cc mx bikes make adults look stupid tring to bump start them so a 250/4 can easily make as much mess :yes:

I'd pay to see some bumping a 2lt V-twin with a supercharger :niceone:

[kwaka_crasher]

I can't be bothered reading all the patchy information spread among all the posts, so did you set the float heights when you had the carbs apart?

[bogan]

I haven't crash started it, I do know that the engine is happy to idle though. I'm holding off on the crash starting idea fro the moment as I can't see it testing anything that I've touched but I might head onto that and crash start to get the engine warm (if it works that is :s)

I think I'm a little lost, how do you know its happy to idle if it wont start and you haven't crash started it? :confused:

[magicmonkey]

I think I'm a little lost, how do you know its happy to idle if it wont start and you haven't crash started it? :confused:

well, it would start but it was bloody hard to do, took ages to get it to catch properly and spring into life. So, I decided to check out the sparks, wound up changing the leads for ones actually meant for a bike (rather than the car leads it was using) and changed some o-rings on the carbs at the same time. Now there's no life at all, engine turns over but doesn't even fire one cylinder off let alone spark into life ...

As for the float heights, that's a job on tonights list. I'll post on how it goes but I have had a brief check while draining the bowls and it looked roughly ok at that point (earlier in the week, after the problems started)

[bogan]

and when it would eventually start, how did it run, missing anywhere?

[MSTRS]

well, it would start but it was bloody hard to do, took ages to get it to catch properly and spring into life. So, I decided to check out the sparks, wound up changing the leads for ones actually meant for a bike (rather than the car leads it was using) and changed some o-rings on the carbs at the same time. Now there's no life at all, engine turns over but doesn't even fire one cylinder off let alone spark into life ...

As for the float heights, that's a job on tonights list. I'll post on how it goes but I have had a brief check while draining the bowls and it looked roughly ok at that point (earlier in the week, after the problems started)

It is possible that the float height is not variable. A lot of Jappers have the float and the fitting for the shutoff needle molded all in one.
As for the rest of the post...there is a lesson in there. DO NOT FUCK WITH 2 different critical things at the same time. 'Fix' one...check...'fix' second if necessary.

[scumdog]

Hmm, you've got good spark, it APPEARS you have fuel getting to the motor - however you take the plugs out after a wiz-wiz-wiz session with the starter motor do they look at all wet/smell strongly of fuel?

Cos if not it's likely that no/not enough fuel is getting into the motor.

And I cannot recall if you mentioned it but how old is the fuel?

[magicmonkey]

and when it would eventually start, how did it run, missing anywhere?

I was actually surprised at how smooth the engine was, the throttle was responsive and the idle purred away like a contented kitten when it had warmed up a bit...

[magicmonkey]

It is possible that the float height is not variable. A lot of Jappers have the float and the fitting for the shutoff needle molded all in one.
As for the rest of the post...there is a lesson in there. DO NOT FUCK WITH 2 different critical things at the same time. 'Fix' one...check...'fix' second if necessary.

heh, I solve problems with complicated things for a living, it's something I know already and really shouldn't have forgotten! Still, some days i'm a complete moron and that day was one of them!

Fortunately the floats are variable, I'll probably be posting a tirade about how crap they are later as it's going to be a tedious job if the do need adjusting (check level, drain petrol, remove bowl, adjust float, fit float, fit bowl, check level, repeat ad infinitum!)

[magicmonkey]

Hmm, you've got good spark, it APPEARS you have fuel getting to the motor - however you take the plugs out after a wiz-wiz-wiz session with the starter motor do they look at all wet/smell strongly of fuel?

Cos if not it's likely that no/not enough fuel is getting into the motor.

And I cannot recall if you mentioned it but how old is the fuel?

Fuel is about a week old so that shouldn't be a problem, I also made sure to drain any old petrol out of the carbs and the tank before putting the new stuff in (installed an in-line filter too, just to be on the safe side)

I think you're probably right about the fuel getting to the engine, I'm just buggered if I know why it isn't getting there!

[MSTRS]

When you installed that filter, did you...
Check it was round the right way.
Ensure the out end was lower than the in end.
Cut enough of the fuel line away so as to not end up with a kink, or an airlock-creating loop.

[neels]

When you installed that filter, did you...
Check it was round the right way.
Funny, I was just thinking the same thing, don't some have a non return valve?

Take the hose off the carbs, turn the tap to prime a see if any fuel comes out.


Fortunately the floats are variable, I'll probably be posting a tirade about how crap they are later as it's going to be a tedious job if the do need adjusting (check level, drain petrol, remove bowl, adjust float, fit float, fit bowl, check level, repeat ad infinitum!)
To check the float level usually I just turn the carb upside down and measure, does that not work on your carbs?

[magicmonkey]

When you installed that filter, did you...
Check it was round the right way.
Ensure the out end was lower than the in end.
Cut enough of the fuel line away so as to not end up with a kink, or an airlock-creating loop.

I did indeed, I checked the fuel flow through it by putting the fuel hose into a plastic bottle and making sure it would flow freely as well. The carb bowls are also plenty full so I can be sure that the filter isn't causing the issue (I think:s)

[bogan]

I was actually surprised at how smooth the engine was, the throttle was responsive and the idle purred away like a contented kitten when it had warmed up a bit...

ok, so it must be work done since, ie fuel filter, o-rings or reassembly error right?

Easy to check if fuel is getting to bowls, just open drain on then and put it on prime, should get a decent flow, not just a trickle, never mind, just saw you checked that.

[kwaka_crasher]

To check the float level usually I just turn the carb upside down and measure, does that not work on your carbs?

I suggest you don't completely invert them but just turn them just beyond the point that the float is resting against the valve on it's seat, otherwise the weight of the float itself can have a surprising effect on the position.

[T.W.R]

I suggest you don't completely invert them but just turn them just beyond the point that the float is resting against the valve on it's seat, otherwise the weight of the float itself can have a surprising effect on the position.

Contrary to what factory workshop & aftermaket manuals say huh?

[magicmonkey]

right, I'm now 99% sure that the spark isn't causing the problem, I've completely been over the wiring and checked the gaps, cleaned the plugs and checked how far the spark will jump on each cylinder, spraying some start ya bastard in each cylinder got a tiny sound of the cylinders firing as well so I think I'm as sure as I can be that it's the carbs causing the problem. Now I just need to work out where they're causing the problem, doh!!!

[kwaka_crasher]

Contrary to what factory workshop & aftermaket manuals say huh?

Genuine Kawasaki manual showing Keihin float height setting adjustment.

Then there's this (http://www.keihin-us.com/am/_media/pdf/slide_valve.pdf) from Keihin themselves.


"This can be done by tilting the carburettor until the float tab just makes contact with the valve pin"

[bogan]

What did you do to the carbs recently? other than drain them heaps

[magicmonkey]

just replaced the o-rings for the fuel line and the vacum line (the two hoses that join and then go to the airbox) that did involve seperating them all though so the re-assembly could have caused the issue. Not sure how though as I didn't even take the bowls of and everything I touched is where it should be.

[kwaka_crasher]

just replaced the o-rings for the fuel line and the vacum line (the two hoses that join and then go to the airbox) that did involve seperating them all though so the re-assembly could have caused the issue. Not sure how though as I didn't even take the bowls of and everything I touched is where it should be.

You never took the bowls off despite dismounting the carbs from the spacer rail in order to replace the rigid fuel line o-rings and no doubt disturbing the sediment in the bowls in the process?

Jesus H. Christ.

I hope you used viton for the seals not nitrile although somehow I doubt it.

[bogan]

this what you have here aye? http://www.cycle-parts.com/selectparts.aspx?Kawasaki_OEM/KawasakiMC.asp%3fType=13&A=562&B=5 It could be theres a vaccum hose bunged in the wrong place, trace them from that and have a look.

[magicmonkey]

You never took the bowls off despite dismounting the carbs from the spacer rail in order to replace the rigid fuel line o-rings and no doubt disturbing the sediment in the bowls in the process?

Jesus H. Christ.

I hope you used viton for the seals not nitrile although somehow I doubt it.

lol, there's no sediment in the bolws and I made sure tha the o-rings I got were fuel proof and ok to use in carbs, even bought them form an auto shop and everything ;)

[magicmonkey]

this what you have here aye? http://www.cycle-parts.com/selectparts.aspx?Kawasaki_OEM/KawasakiMC.asp%3fType=13&A=562&B=5 It could be theres a vaccum hose bunged in the wrong place, trace them from that and have a look.

looks like that's for the ex250 which they were calling a ninja and selling in america at the time which is a shame, thanks for the hunt though, appreciated.

Unfortunately the maunal is a bit shoddy on the subject of vaccum lines as it's only the c model manual (a model one just doesn't seem to exist) and they changed the vaccum line lay out considerably. I'm pretty sure they're all going to the right place though as the engine has been running fine with them pointing where they are (and I can't see any other places for them to go either which is a good sign!)

[bogan]

Well if you're sure its all exactly as it was when it was running fine, why isn't it running fine? Something has to be different, its now narrowed down to no fuel getting to the engine, rip off the airbox and look down into the carbs to see whats hapening when you try and start it up, verify the throttle slides/butterflies are operating as they should etc...

[magicmonkey]

Well if you're sure its all exactly as it was when it was running fine, why isn't it running fine? Something has to be different, its now narrowed down to no fuel getting to the engine, rip off the airbox and look down into the carbs to see whats hapening when you try and start it up, verify the throttle slides/butterflies are operating as they should etc...

probably a really silly question, but what should the slides be doing?

[T.W.R]

Genuine Kawasaki manual showing Keihin float height setting adjustment.

Then there's this (http://www.keihin-us.com/am/_media/pdf/slide_valve.pdf) from Keihin themselves.

I'm not going to bother scanning a posting the whole documents from the service manuals but all do say invert fully till the float hangs down then tilt back until the float valve needle is just seated (the rod in the end of the needle valve should not be compressed) and the importance of that is too insure the valve is seated before taking a measurement

[kwaka_crasher]

lol, there's no sediment in the bolws and I made sure tha the o-rings I got were fuel proof and ok to use in carbs, even bought them form an auto shop and everything ;)

If you didn't remove the bowls I suggest you do not know that. Simply draining them is insufficient.

I've yet to see an 'auto shop' stock anything but nitrile either.


I'm not going to bother scanning a posting the whole documents from the service manuals but all do say invert fully till the float hangs down then tilt back until the float valve needle is just seated (the rod in the end of the needle valve should not be compressed) and the importance of that is too insure the valve is seated before taking a measurement

If you check the post I was replying to initially you'll see that I was saying do not measure the float height with the carb fully inverted. Of course the needle has to be seated.

[magicmonkey]

If you didn't remove the bowls I suggest you do not know that. Simply draining them is insufficient.

I've yet to see an 'auto shop' stock anything but nitrile either.

well, I've had the bowls of now, purely out of paranoia, and double checked them. They're still as clean as the day I cleaned them which is good, at least now I know :)

[kwaka_crasher]

Then moving right along... how are the float heights and float valves & seats?

[magicmonkey]

Then moving right along... how are the float heights and float valves & seats?

well, I checked the fuel levels last night, they were out by a couple of mm on each cylinder which the manual recons is ok so I left them as they were. I've checked the valves before and the rubber part isn't deteriorated at all so that all looks fine. I'm kind of hoping for a eureka moment about now but I think I'm going to put the bike down and have a beer instead, I've had enough of scratching my head for one day!!

[bogan]

probably a really silly question, but what should the slides be doing?

depends on the carby type, if they are fixed directly to the throttle cable, they should move with it, if theres a butterfly in there they should bounce up and down a bit, different hieghts for different throttle positions, and they should all be doing the same thing!

[magicmonkey]

depends on the carby type, if they are fixed directly to the throttle cable, they should move with it, if theres a butterfly in there they should bounce up and down a bit, different hieghts for different throttle positions, and they should all be doing the same thing!

ok, another silly question, am I right in thinking that the part you're callins slides is the plastic tube with the rubber diaphram holding the needles?

[bogan]

thats the one, i figure if they move properly, and air is flowing through the carbs, must be a problem with the fuel in the bowl.

[MSTRS]

Yep. That's what you have with CV type carbs. They may not move when twisting the throttle. On the engine side of the slides, there will be a butterfly in each carb. Those will move. But the engine has to be going to create the vacuum that lifts those slides. The greater the vacuum, the higher the slides go. Which lift the needles further out of the jets, allowing more fuel to get where it's needed.

[magicmonkey]

thats the one, i figure if they move properly, and air is flowing through the carbs, must be a problem with the fuel in the bowl.

sweet, that's a job for the morning when I'm not quite so under the influence then :p

[magicmonkey]

Yep. That's what you have with CV type carbs. They may not move when twisting the throttle. On the engine side of the slides, there will be a butterfly in each carb. Those will move. But the engine has to be going to create the vacuum that lifts those slides. The greater the vacuum, the higher the slides go. Which lift the needles further out of the jets, allowing more fuel to get where it's needed.

well that's reassuring as that's what I thought they were doing and I was starting to get a bit worried that they might be screwed! I'll have a double check tomorrow though, just to be certain ...

[magicmonkey]

well, I checked the floats and they all seemed fine, then I took out the pilot screws and checked them, cleaned them and put them back in (I blew down the hole and covered a few openings with my finger so I knew there wasn't a blockage in the tubes as well). Then I popped the carbs back on and turned the engine over, no joy, surprise surprise!

When I was turning the engine over I noticed that there was oil coming from the engine cover seal which alarmed me, especially as there was quite a bit of oil coming out. So, off comes the engine cover and it turns out that the seal is perishing in quite a few places, it also looks like someone was once aware of this and tried to remedy the situation with a load of silicone sealant. So I'm not wondering, could I be losing compression through this seal and therefore be having problems starting? seems quite likely to me. Either way, it needs replacing with a new one but I'm not 100% sure that would have caused the problem in the first place or if it's just something incidental which happened to go at the same time ...

[bogan]

no, there is a breather from the engine casing to the airbox (usualy) anyway, so no compression down there. Just checking that when you put the pilot screws back in you turned them back the required number of turns? And how did the looking in the carbs from airbox go?

[MSTRS]

When I was turning the engine over I noticed that there was oil coming from the engine cover seal which alarmed me, especially as there was quite a bit of oil coming out. So, off comes the engine cover and it turns out that the seal is perishing in quite a few places, it also looks like someone was once aware of this and tried to remedy the situation with a load of silicone sealant. So I'm not wondering, could I be losing compression through this seal and therefore be having problems starting?

You mean the topmost part of the engine? Above the plugs?
If so, then it is merely the cam cover. Nothing to do with the cylinders part, so no compression loss there. Do replace the gasket tho...gotta keep that oil contained within for the whirly bits.

[bogan]

You mean the topmost part of the engine? Above the plugs?
If so, then it is merely the cam cover. Nothing to do with the cylinders part, so no compression loss there. Do replace the gasket tho...gotta keep that oil contained within for the whirly bits.

i thort he meant a side cover, but good advice either way!

[magicmonkey]

You mean the topmost part of the engine? Above the plugs?
If so, then it is merely the cam cover. Nothing to do with the cylinders part, so no compression loss there. Do replace the gasket tho...gotta keep that oil contained within for the whirly bits.

Yup, that's the cover I mean, got the gasket on order now and I'll pop it on once I get it. It's almost a shame that it wasn't the problem as it would have been a nice easy fix! It has made me wonder if there are other gaskets which could be in the same state (even though all the rest of the rubber looks pretty much fine) I suppose it's time to think about compression testing the thing as I know the spark is fine, I can smell petrol from the exhaust and I've been over the carbs to the point of complete boredom ...

[MSTRS]

Sure, get the compressions checked. But I'm betting that's not your problem. It ran before, yet you haven't touched the head or the valve clearances, so it must be as it was.
You've eliminated the weak spark, and you say the firing order and timing is right, which only leaves...fuel.
Your problem is fuel-related...ergo, something about the carbs is not right.

[bogan]

Sure, get the compressions checked. But I'm betting that's not your problem. It ran before, yet you haven't touched the head or the valve clearances, so it must be as it was.
Your problem is fuel-related...ergo, something about the carbs is not right.

i agree, maybe if the bike was running really poorly last time it could be compression, but it generally doesn't go from good compression to shit that quickly, not without grenading the engine that is, and you'd know if that happend! Have you adjusted any air mix screws and not put them back? pinched a choke cable? anything like that, dunno how familiar with carbs you are, but small changes can greatly affect how/if the engine runs

[magicmonkey]

yup, I pretty much agree with you guys, I'm just getting to a point where I've pretty much gone over everything to do with these carbs and can't find the problem. It's not helped by me not being able to find any diagrams of the carbs either as I'm running a bit blind :s

[kwaka_crasher]

I'm sticking with the problem being fuel related and think you're just overlooking some fundamental problem.

Dare I say it... and I say this very rarely... but perhaps you'd be best to take it to a shop. I don't think you have the patience, understanding & know-how to deal with carburettors at the moment. Getting them looked over properly by someone who knows exactly what they're looking for would be a worthwhile investment.

[magicmonkey]

i agree, maybe if the bike was running really poorly last time it could be compression, but it generally doesn't go from good compression to shit that quickly, not without grenading the engine that is, and you'd know if that happend! Have you adjusted any air mix screws and not put them back? pinched a choke cable? anything like that, dunno how familiar with carbs you are, but small changes can greatly affect how/if the engine runs

I checked the choke cable and it's operating ok. The air screws were turned out 3 turns rather than the 1.5 - 2 which most sites seem to recommend as a starting point so I've tried with both and left them on 1.5 turns for now.

As for the grenading, there was a backfire quite some time ago, I can't remember if that was before or after the problems but I'm pretty sure before. I'm assuming that grenading the engine would be a bit more violent than a backfire though!

[magicmonkey]

I'm sticking with the problem being fuel related and think you're just overlooking some fundamental problem.

Dare I say it... and I say this very rarely... but perhaps you'd be best to take it to a shop. I don't think you have the patience, understanding & know-how to deal with carburettors at the moment. Getting them looked over properly by someone who knows exactly what they're looking for would be a worthwhile investment.

I;m tempted to agree with you at the moment, I've found some carbs for $200 though which would probably be easier and might be cheaper than taking it to a mechanic. Still, I'll leave it until then end of the week before I start spending money I should be saving!

[bogan]

I;m tempted to agree with you at the moment, I've found some carbs for $200 though which would probably be easier and might be cheaper than taking it to a mechanic. Still, I'll leave it until then end of the week before I start spending money I should be saving!

best bet could be to offer a doz or two to a fellow kb'r to come have a look, second opinion could be very useful

[magicmonkey]

well, I'm trying to break this down a bit before I get home tonight so I've got a better plan of what work needs doing. I've been back over this thread and put this together:


Time line of things done so far:

Carbs cleaned - would start after a lot of effort

New battery - would start after a lot of effort - normal behaviour at this point

replaced o-rings on breather and petrol tubes in carbs (took the bank apart but didn't take bowls off) - Also replaced the spark plug leads at the same time - Spark now strong - now not catching though

Backfire - checked electrics, all ok, still not catching

cleaned plugs and checked gap and spark jump, all ok - still not catching

Tried using 'start ya bastard' after removing the plugs overnight in case of flooding - hint of catching but no life

Checked float heights, off by around 2mm on each carb, left alone - still not catching

Checked fuel filter and tested with it removed - still not catching

Cleaned Pilot screws and blew down airways to check for blockages, they were all 3 turns out but tested back on the carbs at 1.5 turns as that seems to be the accepted norm - still not catching

Checked intake manifold gaskets and flow through vacuum tubes, all ok - still not catching


Things to try tonight:

teaspoon of oil down each cylinder - compression

turn the pilot screws out to 3 turns again as it worked fine like that before

Spray some start ya bastard at the carbs while turning over the engine, previously has just been sprayed down the plug holes before putting them back in




So, that's the plan for tonight, if anyone has any other ideas I'll welcome them as always :D

[bogan]

good idea making the list, sure the leads going to the right cylinders? cos that would be an easy fix

[magicmonkey]

good idea making the list, sure the leads going to the right cylinders? cos that would be an easy fix

yup, I'm 100% on that one as I spent an age sat there with the manual going over the wiring (that was my first guess as to what was wrong)

That said, it never hurts to check for the 100th time!!

[magicmonkey]

yup, I'm 100% on that one as I spent an age sat there with the manual going over the wiring (that was my first guess as to what was wrong)

That said, it never hurts to check for the 100th time!!

I've just realised how much of a tit I'm going to feel like if I check it again and realise I've screwed up!!!

[MSTRS]

Best just tell us you tweaked the Flux Capacitor...
Otherwise, we WILL laugh - at you.

[magicmonkey]

Best just tell us you tweaked the Flux Capacitor...
Otherwise, we WILL laugh - at you.

well, at this point I've pretty much accepted that any fix will be to do with something I've cocked up, I'll be deserving a healthy laughnig at when I work it out regardless of what it was. Still, I'll tell you all, might as well man up to it :p

[MSTRS]

Onya.
We WILL hold you to that.

[neels]

I've just realised how much of a tit I'm going to feel like if I check it again and realise I've screwed up!!!

Can't hurt to recheck the plug leads just in case.

I notice you don't have new spark plugs on the list, before you spend $200 on more carbs you might like to try replacing them (or at least one of them), even if they look OK if it's been flooded and attempted to start numerous times they could be tracking across the plug under compression and killing your spark. I spent ages trying to get an old bike going on plugs that looked fine, checked everything else with no joy, replaced the plugs with new ones and away she went.

[magicmonkey]

Onya.
We WILL hold you to that.

well, it'd just be plain rude to get this much help of people and not give them a laugh in return ;)

[magicmonkey]

Can't hurt to recheck the plug leads just in case.

I notice you don't have new spark plugs on the list, before you spend $200 on more carbs you might like to try replacing them (or at least one of them), even if they look OK if it's been flooded and attempted to start numerous times they could be tracking across the plug under compression and killing your spark. I spent ages trying to get an old bike going on plugs that looked fine, checked everything else with no joy, replaced the plugs with new ones and away she went.

I get what your saying, although the engine was running fine with these plugs before I decided to be an idiot and change 2 things at once so I'm pretty sure these are ok for the moment. it'll cost me just over $100 to replace them as well which is a bit of a pain in the arse!!

[Grasshopperus]

Nah, $60max for 4 x CR9E plugs mate.

Buy 24 beers and some bbq food and, invite a KB'er in your area over, pay for his taxi home and spend the day. I'd do it if I was in your area.

[magicmonkey]

well, yesterday morning the bike fired into life quite happily and was good to go. Seems that it was the pilot screws which fixed the problem :)

Unfortunately I'm now back at the starting point though which means that it'll start but only after a lot of hassle and a shit load of choke. Still, it will start, that's one hell of a bonus from my point of view :D

last night a KB'er popped round as well, spent ages working on the bike and taught me a hell of a lot about engines. The timing was out by 2 teeth, rather than the 1 tooth which apparently gives more power in the mid-range on this model, so that got changed back to factory. The fuel tap got a good checking over. Fuel to the cylinders got verified (I was pretty sure but it's good to have a second opinion). the electrics got a check over and the reg/rec taken out of the system to verify that it wasn't causing the problem, and a shit load of other checks I never would have thought of on my own.

At the moment it looks like it's still the sparks which are causing the problem so I'll be off to pick up a new set of plugs later today (something that was going to get done before I used the bike anyway so it's not going to put me out of pocket, which is nice:)). If that doesn't work then it'll be time to check over the entire wiring loom, cleaning and checking all the connectors, and if that still doesn't work then it'll be time to check the individual components of the electrical systems to see if one of them is faulty.

So, there's either a tiny amount of work or a lot of work ahead of me in the next few days but it's starting to come together and I've got some direction rather than just blindly poking around and hoping that something will work so I'm pretty chuffed :D:D

so, big thanks to everyone for their advice, I'm not too sure I would have been able to get this far without it, I'm sure I'll be asking for more pretty soon as well ;)

[MSTRS]

Those pilot screws are quite important, you now know. Where they are set can be critical - controls the air/fuel mix prior to the mainjets coming into play.

[magicmonkey]

Those pilot screws are quite important, you now know. Where they are set can be critical - controls the air/fuel mix prior to the mainjets coming into play.

yup, looks like I've learned that one now! I'll probably have to play around with them a bit more once I've got the electrical problem sorted as I think it's probably running quite rich at the moment. Still, that can be a problem for another day, for now I just need to find me a bike shop which is open today, doh!

[MSTRS]

Today? Unlikely.
NGK CR9E - quite common. see here what they fit (http://cgi.ebay.com/ebaymotors/NGK-CR9E-6263-4p-Spark-plugs-749-998-ZX750-GSX1300-FZ1-/270538943890)
Should find at a service station

[magicmonkey]

Today? Unlikely.
NGK CR9E - quite common. see here what they fit (http://cgi.ebay.com/ebaymotors/NGK-CR9E-6263-4p-Spark-plugs-749-998-ZX750-GSX1300-FZ1-/270538943890)
Should find at a service station

yeah, just rang around the bke shops and none are open, doh! Still, supercheap are doing a sale tomorrow so I might be able to pick some up for cheap which would be good.

[T.W.R]

:yawn:.................:shutup:

[magicmonkey]

So, thanks to Richards Motorcycles (brilliant little shop :)) I now have new spark plug and they're all happily in their holes sparking away, joy.

It still isn't starting very easily though, it needs the choke full on and the throttle seems to dip the revs until the engine is warm (that's just plain weird as far as I'm concerned!) The spark also isn't quite as strong as I was expecting it to be so I'm starting to think that there might be an earth problem. I've already cleaned the main connection onto the engine but I popped that off and made sure it was still ok and I'm pretty satisfied with that. I suppose the next place to start is the wiring that has been fiddled with by a previous owner (an even worse mechanic than me, if you can imagine such a thing) At the moment I've narrowed down the areas I know have been tinkered with as he used after-market sleeves for the wires rather than keeping the old sleeves. So, bits he's fiddled with are:


pick up coil/oil pressure switch
fan switch
side stand switch
neutral switch/alternator/temp switch
handlebar controls (both sided)


Those are listed by the way they come out of the wiring loom, i.e. I know he's touched at least one of the components on each line.

At the moment I'm starting ti think that I should look at things which actually have an earth (the current at the battery is doing what it should be when running and off so I'm reasonably sure that current is bleeding rather than not being produced). I doubt it's the handlebar controls (only the kill switch should go straight to earth and that would just stop the bike) so I'm now thinking that the pick up coil is the most sensible place to start looking, I need to get a multimeter that does resistance though as my current one only does everything else, doh!

So, other than the electrics and the strange problem with the throttle dipping revs until the engine is warm, things seem to be more or less ok, I think ... I'll need to check the valve clearances and blanace the carbs and set the pilot screws properly and sort out the suspension and clean everything and fix the fairing and paint the fairings and blah blah blah but it seems almost on track and should be ridable once I've got this starting nailed ...

[Jonno.]

Err, doesn't that sound like a fueling issue?

[kwaka_crasher]

Yep, sounds like it. Too lean. Probably pilot screws.

[magicmonkey]

well, a lot of time and a lot of help later I've finally got it starting :D it'll even idle without the choke on now as well! Now I've moved on to carb balancing but I'll start another thread on that, this one is getting a bit long in the tooth!

Thanks for the help and advice guys, much appreciated :D:D

[Coldrider]

There are some carb balancing threads already available on KB.

[magicmonkey]

There are some carb balancing threads already available on KB.

yup, and I'll be reading through them, and checking you tube before I hassle eveyone too much :)

[Paul in NZ]

You can still borrow my gizmo btw ;-)

[magicmonkey]

You can still borrow my gizmo btw ;-)

Thanks again for the offer, I've managed to borrow one from someone who lives round the corner though so I'm all good :D

[Jonno.]

So was it fueling?

[magicmonkey]

So was it fueling?

well, the timing was out by 2 teeth, the jetting was all over the shop, the spark plugs and leads all needed replacing, the rocker cover was leaking oil into a spark plug well (only an o-ring problem thankfully!). There were quite a few things wrong in the end but none of it was so extreme as to write the bike off and most of it was done without having to buy new parts which is good. All in all, it's been a good learning experience so far and once I've got the carbs all balanced properly I will have learnt a heap more :)

I shaln't pretend that I didn't cause any problems myself though, I've done tons of stuff wrong! Still, i've learned from that too so it's all good ...

[Bad Gixxer]

I've only just come across this thread - you'll be pleased to know that we've all probably had similar experiences - the beauty of it is that in trying to fix one single thing, you end up learning heaps of invaluable hands-on information.

I won't tell you about the time I reassembled my 2-stroke RZ350 after a full carb and engine rebuild - everything ran just beautiful except it had no mid range power when I reassembled it. After 3 months of trying to diagnose the problem (virtually a full pull down, and I must have had the carbs dismantled about 10 times and cleaned to within an inch of their life!!), I finally discovered that I'd put the YPVS valves in the wrong way round - this meant that the power valve was open when it should have been closed, and vice versa. The funny thing was, I thought this may have been a possibility on day one, but my ego told me that there's no way I would be so stupid!

Moral - if your ego tells you something, ignore it!

[magicmonkey]

I've only just come across this thread - you'll be pleased to know that we've all probably had similar experiences - the beauty of it is that in trying to fix one single thing, you end up learning heaps of invaluable hands-on information.

I won't tell you about the time I reassembled my 2-stroke RZ350 after a full carb and engine rebuild - everything ran just beautiful except it had no mid range power when I reassembled it. After 3 months of trying to diagnose the problem (virtually a full pull down, and I must have had the carbs dismantled about 10 times and cleaned to within an inch of their life!!), I finally discovered that I'd put the YPVS valves in the wrong way round - this meant that the power valve was open when it should have been closed, and vice versa. The funny thing was, I thought this may have been a possibility on day one, but my ego told me that there's no way I would be so stupid!

Moral - if your ego tells you something, ignore it!

well, at the moment I've got it to the point that it'll start, but not very well. I noticed some smoke coming from the carb on cylinder 2 and found that it was down on compression so I'm now trying to decide if I should take the head off and do a proper rebuild on it or just flog it for parts. It seems I'm about to learn far more than I planned on learning!

[bogan]

well, at the moment I've got it to the point that it'll start, but not very well. I noticed some smoke coming from the carb on cylinder 2 and found that it was down on compression so I'm now trying to decide if I should take the head off and do a proper rebuild on it or just flog it for parts. It seems I'm about to learn far more than I planned on learning!

sounds like an intake valve isnt sealing properly, just thrash the shit out of it and it may come right

[magicmonkey]

sounds like an intake valve isnt sealing properly, just thrash the shit out of it and it may come right

I'm pretty sure that the intake valves are seating fine, smoke only puffs out when they are open. I have a sneaky feeling that there's and exhaust valve stuck but I'm open to being wrong about that!

[bogan]

I'm pretty sure that the intake valves are seating fine, smoke only puffs out when they are open. I have a sneaky feeling that there's and exhaust valve stuck but I'm open to being wrong about that!

if the compression is down on that one cylinder is seems likely it is valve not sealing properly, and valves dont stick (closed anyway) unless there is something seriously wrong, like a broken rocker arm. If smoke is puffing out the carb it seems likely that there is something wrong with the intake valve (should always be in vacuum there)

[magicmonkey]

if the compression is down on that one cylinder is seems likely it is valve not sealing properly, and valves dont stick (closed anyway) unless there is something seriously wrong, like a broken rocker arm. If smoke is puffing out the carb it seems likely that there is something wrong with the intake valve (should always be in vacuum there)

Ok, that makes sense. Seeing as this is an overhead cam engine I'm assuming that this could be something like a wrong sized shim. There is clearance on the intake valves and I've turned the engine over by hand and watched them move, they seem to be functioning properly as far as I can tell from those basic tests ...

[bogan]

Ok, that makes sense. Seeing as this is an overhead cam engine I'm assuming that this could be something like a wrong sized shim. There is clearance on the intake valves and I've turned the engine over by hand and watched them move, they seem to be functioning properly as far as I can tell from those basic tests ...

firstly, what are the compressions in each cylinder?
as its an engine that used to rune fine, i dont think itll be a shim or something similar, more likely when in storage the valve was open and aquired some corrosion, which is why i recomend thrashing it for a while to get rid of it, beats spending more money on it or selling it off as parts anyway!

[magicmonkey]

firstly, what are the compressions in each cylinder?
as its an engine that used to rune fine, i dont think itll be a shim or something similar, more likely when in storage the valve was open and aquired some corrosion, which is why i recomend thrashing it for a while to get rid of it, beats spending more money on it or selling it off as parts anyway!

When you say 'thrash it for a while' how long are you talking abotu, a ride around the coast or 10 minutes in the garage reving with no load...

[bogan]

When you say 'thrash it for a while' how long are you talking abotu, a ride around the coast or 10 minutes in the garage reving with no load...

it really depends on how bad the problem is, how low is the compression on that cylinder? how much smoke comes out, does it get worse at revs etc.....

[magicmonkey]

it really depends on how bad the problem is, how low is the compression on that cylinder? how much smoke comes out, does it get worse at revs etc.....

Compression is about half of what it should be and the smoke can come out quite a lot. I get the impression that it's something which has been getting progressively worse as it sems to have been going on for a while but I've only noticed it recently, it does seems to get worse at revs as well ...

[bogan]

Compression is about half of what it should be and the smoke can come out quite a lot. I get the impression that it's something which has been getting progressively worse as it sems to have been going on for a while but I've only noticed it recently, it does seems to get worse at revs as well ...

um, why does it seem to have been going on for a while if you've only noticed it recently?

basically, you have three options, try to kludge it, pay heaps to fix it, or sell it as parts.

[Bad Gixxer]

before you bin the whole project, and since you've come this far anyway, i suggest you get some Wynns Valve Lifter Fluid and try some of that in your tank. Take it for a good ride around the block a few times so yo'ure never too far from home, keep the rev's high but variable, and see if this clears the resin or verdigree on the valve stem and/or seat. If that doesn't fix it, then for the sake of a new gasket, just pull the head and see if it's a burnt out valve or whatever. if you find it'a a basket case and not worth repairing, then bin it or sell it off, or you might find that it's just a sticky valve that needs dismantling and cleaning properly. Look at it this way, it might be a cheap fix that makes all your other efforts worthwhile. Pulling a head off is no big deal, you may be even able to recondition the gasket and re-use it.

And while the head's off anyway, give it a valve grind and learn something else that will stand you in good stead for future mechanical adventures!! i remember my Old man making me grind cylinders by hand, wouldn't let me use a drill. He reckoned that was the only way to get it to a glass finish, right down to the final polish with Jeweller's Rouge. Then the overnight Kerosene test with the valves just sitting in the head loosely - he reckoned if the kero could get past the metal-to-metal seal without the springs in, then it wasn't good enough. Bit of a perfectionist my Old Man - they didn't call him two-tenths Ted for nothing! My point is, if you surrender now then you'll either be reluctant to start another job, or experience similar difficulties and find it TOO easy to pack it in. Don't let it get the better of you and make it a matter of principle, and bugger the cost (within reason).

[magicmonkey]

yup, finally managed to get the head off over the weekend, looks like th problem has been caused by a carbon build up on the valve seats rather than any physical damage to anything under there so I'm quite happy about that :) Now all I need is a spring compressor, then I can give everything a good clean and put it all back together. I've decided not to take the cylinders out though as there's no sign of anything wrong that far down in the engine and I don't really want to run the risk of causing myself more problems that I have to, especially considering that you can't buy new rings any more. Hopefully, once that lot has been done it'll be running well and I'll finally be able to put it back on the road.