Trouble starting...

[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

[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!!