GN250 running too rich?

[globe]

I have a 2007 GN250, i Have swapped out the exhaust on it for an aftermarket one. I am finding that if i have the idle around 1500rpm (as is meant to be) it bogs when warm and i open the throttle to pull away lights etc. I have screwed in the a/f screw as much as possible as I believe it is running rich (the choke is fully pushed in also). I believe it is running rich as the stalling problem gets worse when the a/f screw is turned out to 2+ turns, and when I fire it up after it has bogged (or if I manage to catch it before it stalls) then the smoke coming from the back is black. This generally happens when the bike has had chance to warm up. If I wind up the idle screw (the one that adjusts the resting position of the accelerator) it seems OK but of course it is revving its tits off at 2500-3000rpm.

I tried removing the air filter and twisting the throttle then to see if that was preventing the air getting through the system but made no difference.

ANn suggestions or is my next stop a carb removal and clean (checking the pilot jet thoroughly),

Cheers

[Akzle]

you're going to want to rejet that motherfucker

[globe]

you're going to want to rejet that motherfucker

You reckon they're rooted or too large?

[Akzle]

you're going to want to take it to someone who knows what the fuck they're about.

[caspernz]

you're going to want to take it to someone who knows what the fuck they're about.

You mean to say messing with the exhaust, which alters the stoichiometric ratio beyond what current jets can be adjusted to, requires a bit of clever thinking...:oi-grr::wacko:

[Akzle]

You mean to say messing with the exhaust, which alters the stoichiometric ratio beyond what current jets can be adjusted to, requires a bit of clever thinking...:oi-grr::wacko:


well i don't know about any of that fandangled stoichiometry, but i do know that the carburettor pixies get upset when you change the flow and will often go on strike. and if you have to ask "why" then you probably need a professional pixie-whisperer.

[globe]

you're going to want to take it to someone who knows what the fuck they're about.

IS that what your wife said to you mate?

[FJRider]

IS that what your wife said to you mate?

She said "I'm not touching that" ... so it was close ...

[FJRider]

You reckon they're rooted or too large?

Sounds like another "it was running fine until I changed the wiper blades" type issue ... How old is it and how many km's .. ???

[globe]

Sounds like another "it was running fine until I changed the wiper blades" type issue ... How old is it and how many km's .. ???

Yeah nah, it was a bit rough before I changed the exhaust, I always ran it at uber high idle (like 2500rpm) - now i'm trying to get serious and learn some shit at the same time, which is fun, but 10 years ish, done 23,000kms according to carjam. Cheers

[FJRider]

Yeah nah, it was a bit rough before I changed the exhaust, I always ran it at uber high idle (like 2500rpm) - now i'm trying to get serious and learn some shit at the same time, which is fun, but 10 years ish, done 23,000kms according to carjam. Cheers

Put the old exhaust back on and see if that changes anything.

[globe]

Put the old exhaust back on and see if that changes anything.

Good idea, however.....yup......it is no longer in my possession.....bugger

yeah i know dumb move

[Akzle]

IS that what your wife said to you mate?

no. but your wife did.
i think being over 3", she just didn't know what to do with it...:bleh: :niceone:

[Ginge09]

Idle speed at 1500rpm seems high to me, despite what your manual says. Uber high idle speeds of 2500 are ridiculous for a single four stroke like this.

Idle speed is whatever setting allows the engine to maintain flywheel rotation and overcome flywheel inertia, and provide a clean response when you open the throttle.

I think your idle is too high and you're not actually running on the pilot circuit at all when at idle. Probably running on slide cut away.

Warm the bike by riding down to your local bike shop. Buy a new spark plug. Come back and leave the bike running. Drop the idle as low as you dare, then tune the air/fuel screw for best fast running at idle. Drop idle some more, fine tune air/fuel screw again. It may not change. Small fractions of a turn are possible of making a big difference. Now you should be running on the pilot circuit.

Stop bike. Fit new plug. Bike should start and idle well. You can repeat the above process again with the new plug if you like but probably not necessary. If it doesn't idle something is probably blocking air or fuel feed. Could also be valve clearances but if it was running okay before you changed exhausts then they should still be okay.

You need to understand what twiddling with the air/fuel screw actually does. Does it control air or fuel feed?

Your new exhaust may be relevant further up the throttle position range but on this motor I doubt it will change much in the idle circuit.

[globe]

Idle speed at 1500rpm seems high to me, despite what your manual says. Uber high idle speeds of 2500 are ridiculous for a single four stroke like this.

Idle speed is whatever setting allows the engine to maintain flywheel rotation and overcome flywheel inertia, and provide a clean response when you open the throttle.

I think your idle is too high and you're not actually running on the pilot circuit at all when at idle. Probably running on slide cut away.

Warm the bike by riding down to your local bike shop. Buy a new spark plug. Come back and leave the bike running. Drop the idle as low as you dare, then tune the air/fuel screw for best fast running at idle. Drop idle some more, fine tune air/fuel screw again. It may not change. Small fractions of a turn are possible of making a big difference. Now you should be running on the pilot circuit.

Stop bike. Fit new plug. Bike should start and idle well. You can repeat the above process again with the new plug if you like but probably not necessary. If it doesn't idle something is probably blocking air or fuel feed. Could also be valve clearances but if it was running okay before you changed exhausts then they should still be okay.

You need to understand what twiddling with the air/fuel screw actually does. Does it control air or fuel feed?

Your new exhaust may be relevant further up the throttle position range but on this motor I doubt it will change much in the idle circuit.

Cheers mate, great response. I cleaned the carb thoroughly and it seems to have made a difference. Haven’t had chance to take it for a proper spin yet but here’s hoping 👍

[Ginge09]

So that should tell you that your new exhaust is going to be fussier on carb settings than the original. Dirty carb didn't matter on the old pipe but does on the new one.

Suggest your old pipe was clogged or leaking so back pressure or flow was not optimal. Now with the new pipe you have some tuning to do.

Go through the procedure in my previous post now the carb is clean.

[globe]

Looks like i spoke too soon....*sad face*

Finally got chance to take it for a spin today, was bogging a low revs and low gears (sub 4-5k revs, in first second and third, didnt get into 4th or above). Thought it mightve been the inline fuel filter, came home took it out, no difference. Opened the air/fuel mix screw half a turn, didnt seem to get much better. Tried winding the idle screw in and i noticed it didnt stall as one would expect.

Will check for air leak following reinstall of carb (the back hose - air filter side - was a bit tricky to get on).

Other than that any other thoughts, suggestions? Cheers

[Ginge09]

Doubt that's an air leak. Air leaks tend to induce a lean condition.

Blocked air filter? Try running it without one, although if it didn't stall when you wound the idle down then it's not running on the pilot circuit. Is the slide hanging in the throttle body ( check by sticking your finger into the throat of the carb).

Is the throttle cable adjustment too tight ( if you have one)

What sort of carb is it, Mikuni round slide?

[globe]

Doubt that's an air leak. Air leaks tend to induce a lean condition.

Blocked air filter? Try running it without one, although if it didn't stall when you wound the idle down then it's not running on the pilot circuit. Is the slide hanging in the throttle body ( check by sticking your finger into the throat of the carb).

Is the throttle cable adjustment too tight ( if you have one)

What sort of carb is it, Mikuni round slide?

I don't think its a mikuni, I think the previous owner must've out an aftermarket on it - no ID that I can see from anywhere.
By bogging, I mean it slows down has not guts even with the throttle out - presuming this is the international definition of bogging, then is this an indication of running to rich still?
The odd thing is when it is up on it stand and idling away nothing appears too untoward, still get it stalling every now and again when I twist the throttle but nothing like it was before the clean.

The throttle cable adjustment feels OK but I can loosen it off a bit to see if that makes any difference (why do you think that would affect this, or is it one of those odd things that can't be explained but sometimes do).

Will have a look at the throttle slide over the weekend.

Cheers

[Akzle]

is this an indication of ...

plug chop .

[globe]

plug chop .

Not sure what this means, are you recommending I check the plug to see if this looks lean, rich etc? If this is the case I has hardly done any kms since I cleaned the carb (and replaced the plug) maybe 5-10kms, would this be enough to show the running condition you think? Cheers

[Akzle]

http://www.lmgtfy.com/?q=plug+chop

[Honest Andy]

plug chop .

+1
You don't have to cut it but at least look at it, it's a quick and easy rough guide. You've changed a bit of stuff now so maybe it's running lean, it'll bog down with fuel starvation too, especially under power.
And don't forget that it's really easy to introduce a second problem while trying to fix the first one.
So put the filters back in after you've done the test so you don't block up the jets...

[globe]

Thanks for the suggestions thus far chaps much appreciated. Quick question, if i have the idle screw out too far so it is idling high (say 1500rpm upwards) would it still cut out once the air/fuel screw is adjusted to try and lean it up? Wondering whether that might be an issue that is one of the reasons that it wont stall on the a/f screw? Hope that makes sense ?

The other thing that may or may not be of relevance is that I don't need the choke to start it most times, its just fires up first time.

Even though it is frustrating its great fun learning

Cheers

[globe]

http://www.lmgtfy.com/?q=plug+chop

Good one, you couldn't tell me the weather forecast for Auckland for Sunday too while you're googling stuff for me could you? :niceone:

[Ginge09]

Quick question, if i have the idle screw out too far so it is idling high (say 1500rpm upwards) would it still cut out once the air/fuel screw is adjusted to try and lean it up?

Yes. If you wound the air/fuel screw far enough. Enough to either completely open or completely close whatever orifice it is designed to meter.

But if it doesn't do much then your not running on that orifice. Your running on the next metering device in the chain which is probably the slide. Air/fuel screw only adjusts idle and transition to slide or needle jet normally. Hard to know without knowing your carb.

This is why you check your throttle cable adjustment. If it is too tight the slide is not closed at idle and is active (hanging off the cable) and passing air into the throat of the carb. You are using the slide as your idle circuit. The pilot should be your idle circuit, the slide is secondary circuit then the needle and then the main jet. Roughly speaking.

So stick your finger into the throat of the carb and make sure it is bottoming out when on zero throttle. It should snap closed when you let go of the twist grip. No gaps.


I don't need the choke to start it most times, its just fires up first time.


It's summer. If you live North of the 45th parallel that would be normal. In winter up your way may also be normal.

Take a photo of your carb and post it. Be a good lad.

Stick with it!

[globe]

Here you go. I’ll post up some more when I take it off again this weekend

[Akzle]

ah yes. it's all clear from the pictures. your hooferdacky is misaligned with the whoserwhatsit, you need to kerfluffle the thingamabob widdershins

[Honest Andy]

Ahh. Vacuum slides. Pictures help :niceone:
As Ginge says, check the action of the throttle, which is the butterfly, make sure it returns fully and without hesitation.
Disassemble and clean. Really thoroughly. Especially the jets but also make sure the piston slide is really free with no hesitations. Reassemble making sure there are no air leaks through bad seals.
Return all adjustments back to factory settings...

[Ginge09]

That's a TK carb by the look of the TK marking on the side...Google is your friend.

I thought they had Mikuni's originally but who knows.

[globe]

That's a TK carb by the look of the TK marking on the side...Google is your friend.

I thought they had Mikuni's originally but who knows.

Did some googling, think it might be a Nasaki, sound familiar? I’ll be buggered if I can’t fi d any data on them except on aliexpress...

[globe]

Just pulled the carb off. Photos down each hole (oo-er!!)335442335443

Slide works really smoothly

[globe]

Plug colour, (not from a chop test, just from cruising)

335451

[Honest Andy]

Good call, way rich.
Check the choke action
And remove the jets for cleaning

[globe]

Good call, way rich.
Check the choke action
And remove the jets for cleaning

Cheers Andy. Cleaned the carb and jets again today. No difference. The odd thing is that before I took the carb out and cleaned it the other week the only issue was stalling when hot and twisting the throttle at the lights occasionally. I think the pilot jet was a bit clogged and I flushed that out, but now the issue seems to be 1/4 to 3/4 ish throttle (5-6k rpm)....sigh

[Akzle]

Cheers Andy. Cleaned the carb and jets again today. No difference. The odd thing is that before I took the carb out and cleaned it the other week the only issue was stalling when hot and twisting the throttle at the lights occasionally. I think the pilot jet was a bit clogged and I flushed that out, but now the issue seems to be 1/4 to 3/4 ish throttle (5-6k rpm)....sigh

you have of course done a search for "motorcycle carburettor tuning" eh?

jesus it's like spoon feeding.
www.dansmc.com/carbs2.htm

[caseye]

you have of course done a search for "motorcycle carburettor tuning" eh?

jesus it's like spoon feeding.
www.dansmc.com/carbs2.htm

Arkle! is that really you? assisting a new member to make a difference, wow. never thought I'd see the day. good work muddatrucker.

[globe]

you have of course done a search for "motorcycle carburettor tuning" eh?

jesus it's like spoon feeding.
www.dansmc.com/carbs2.htm

Read it heaps of times, it’s a good site aye.

[Akzle]

now the issue seems to be 1/4 to 3/4 ish throttle (5-6k rpm)....sigh

right. so you've "read it heaps of times"

so you're going to do what now?

[globe]

..............

[globe]

right. so you've "read it heaps of times"

so you're going to do what now?

Looks like I am going to keep struggling on even though i have read it heaps of times, reading it doesn't mean it suddenly starts working and i suddenly know what the cause of the problem is....not for me anyway

[globe]

So here's the latest. Moved the needle up one notch (lowered the clip by one notch) to richen it up after deciding the misfiring was a result of lean-ness. That made it run fine through all the range of throttle except WOT. Little bit of stalling on idle when the throttle is twisted, but havent tried to adjust the fuel/air screw yet.

The really annoying thing now is that there is a slight drip from the overflow on the carb but only when the bike is on its side stand not middle stand, I'm guessing the float is too high and hence it drips over when on an angle, other than that I guess the gasket could be rooted.

Small steps but at least there in the right direction :niceone:

[Akzle]

So here's the latest. Moved the needle up one notch (lowered the clip by one notch) to richen it up after deciding the misfiring was a result of lean-ness. That made it run fine through all the range of throttle except WOT. Little bit of stalling on idle when the throttle is twisted, but havent tried to adjust the fuel/air screw yet.

The really annoying thing now is that there is a slight drip from the overflow on the carb but only when the bike is on its side stand not middle stand, I'm guessing the float is too high and hence it drips over when on an angle, other than that I guess the gasket could be rooted.

Small steps but at least there in the right direction :niceone:

rbcifgip.

now yer getting it.

probly a bigger stoikofairy in the middle will do ya. then you clip up again. and readjist the pilots.
i'd say you're right with the float assessment.

well done grasshopper san.

[globe]

rbcifgip ???

[Akzle]

rbcifgip ???

means "rep, but c*ssina is a fuckwit and gremlin is a pussy" you'll understand in good time son. don't concern youself with it now.

just keep spinning spanners on the mighty gn.

[globe]

OK, I'm getting frustrated now. Its still dripping from the carb overflow, have raised the float height a couple of times now (and tested with the bowl off running fuel from a funnel). I have taken the little fuel needle that is attached to the float apart and "lengthened" the spring as it didn't seem to be that stiff.

Not sure where to from here, I am assuming there are no 'o' rings missing from the fuel needle thingy (there isn't one on there).

Any thoughts/suggestions (before I take to it with a hammer)? Cheers

[Akzle]

OK, I'm getting frustrated now. Its still dripping from the carb overflow, have raised the float height a couple of times now (and tested with the bowl off running fuel from a funnel). I have taken the little fuel needle that is attached to the float apart and "lengthened" the spring as it didn't seem to be that stiff.

Not sure where to from here, I am assuming there are no 'o' rings missing from the fuel needle thingy (there isn't one on there).

Any thoughts/suggestions (before I take to it with a hammer)? Cheers

take your float out and chuck it in a bucket of petrol and see if it does... float

[globe]

take your float out and chuck it in a bucket of petrol and see if it does... float

I’ll give this a go but not convinced it’s the issue, it’s only started doing this following ,me giving the carb a good clean, but hey good suggestion, I’ll check it out

[Akzle]

wait you say raised the float height twice... like letting more fuel in?
or raised as in it sits higher when the carb is upside down

[globe]

wait you say raised the float height twice... like letting more fuel in?
or raised as in it sits higher when the carb is upside down

Yeah sorry that wasn’t very clear. I adjusted th float so that it shuts of the fuel earlier.

[oldiebutagoody]

If your carb leaks at standstill you have either a fuel tap that is not shutting off properly, or a fuel tap that does not shut off properly in combination with a leaking float valve needle. Either way the float needle is the more immediate problem. It will cause too much fuel to be in the system at any given time and make it run rich. Trying to tune this out of the carb will end up with you chasing your tail as nothing will be ideal in all of the operation ranges.

Float needles have a rubber tip (rubber goes hard with age/heat/solvent exposure/time) which is supposed to be pushed up by the floats when fuel fills the bowl. If the float level is not set to (whatever the manual states) ....it will either starve or flood. If in combination with incorrectly set float level you have a float needle that has gone hard, or is binding in its housing then you get heavy fouling of the spark plug.

Simplest and least frustrating remedy is order replacement float jet/needle assembly (buy OEM and forget EBAY/TardMe), reset float level to factory spec, throw away the plug and insert new one. Honestly its not a lot of money, probably less $$$ than you have poured down the drain in fuel wastage.

Ask me how I know this..............

Things wear and need replacing with age (mechanical things also). A GN250 is not a complicated machine, get a manual or download one off t'internet, google search terms like " GN250 running rich, carb leaking fuel"

[globe]

If your carb leaks at standstill you have either a fuel tap that is not shutting off properly, or a fuel tap that does not shut off properly in combination with a leaking float valve needle. Either way the float needle is the more immediate problem. It will cause too much fuel to be in the system at any given time and make it run rich. Trying to tune this out of the carb will end up with you chasing your tail as nothing will be ideal in all of the operation ranges.

Float needles have a rubber tip (rubber goes hard with age/heat/solvent exposure/time) which is supposed to be pushed up by the floats when fuel fills the bowl. If the float level is not set to (whatever the manual states) ....it will either starve or flood. If in combination with incorrectly set float level you have a float needle that has gone hard, or is binding in its housing then you get heavy fouling of the spark plug.

Simplest and least frustrating remedy is order replacement float jet/needle assembly (buy OEM and forget EBAY/TardMe), reset float level to factory spec, throw away the plug and insert new one. Honestly its not a lot of money, probably less $$$ than you have poured down the drain in fuel wastage.

Ask me how I know this..............

Things wear and need replacing with age (mechanical things also). A GN250 is not a complicated machine, get a manual or download one off t'internet, google search terms like " GN250 running rich, carb leaking fuel"

Cheers, did as you suggested and will get replacement needle. As for the float height may be more tricky, it’s a frankenbike so non standard carb. It’s got TK stamped on the side but finding one that matches on the web is proving to be troublesome, but yes new float needle to begin.

Anyone know of any TK carb suppliers in AKL (preferably the shore but not essential) where I might be able to take it in to get it ID’d. Cheers

[oldiebutagoody]

Cheers, did as you suggested and will get replacement needle. As for the float height may be more tricky, it’s a frankenbike so non standard carb. It’s got TK stamped on the side but finding one that matches on the web is proving to be troublesome, but yes new float needle to begin.

Anyone know of any TK carb suppliers in AKL (preferably the shore but not essential) where I might be able to take it in to get it ID’d. Cheers

Here's a thought..........try Bike Busters wreckers in Ngaruawahia to see if there is a GN250 standard carb you can put on it.

My bad, I hadn't read entire thread and jumped in not realizing you have non standard parts.

I ran a GN250 as a courier bike many many years ago when I first started. Hard to think of a more reliable trouble free model :Punk:

[globe]

So I am going to keep musing on this thread as i am sure at some point in the future some other forum rat will come across the same issue, sharing is caring so I'm told.

Took the carb apart again this morning after watching Andy Mechanics excellent youtube video last night on carb leaks. I had a look at the o ring around the fuel needle housing thingy. It slipped in and out easily suggesting there wasnt a tight fit between the o ring and the casting so i took it off and yes its as brittle as thousand year old toffee. Will replace this week and see if that stops the dripping from the carb.

Doesn't help that I jumped to float level as being the cause of the leak so now it is all over the show so need to reset that. Emailed a supplier of TK carbs in the UK, he tells me the carb is (surprise surprise) non-original and some Chinese version so no float height data (that he has sent me yet). So I will try and set the float level a few mm's below the gasket level (which will be about 7-10mm below the overflow) and see where to from there. I understand using a clear tube off the overflow outlet is the best approach to this, unless there are some other suggestions.

Andy, if you read this forum, that float height video you talked about would be really really useful right about now mate :2thumbsup

[Autech]

Good idea, however.....yup......it is no longer in my possession.....bugger

yeah i know dumb move


I don't think its a mikuni, I think the previous owner must've out an aftermarket on it - no ID that I can see from anywhere.
By bogging, I mean it slows down has not guts even with the throttle out - presuming this is the international definition of bogging, then is this an indication of running to rich still?
The odd thing is when it is up on it stand and idling away nothing appears too untoward, still get it stalling every now and again when I twist the throttle but nothing like it was before the clean.

The throttle cable adjustment feels OK but I can loosen it off a bit to see if that makes any difference (why do you think that would affect this, or is it one of those odd things that can't be explained but sometimes do).

Will have a look at the throttle slide over the weekend.

Cheers


Cheers, did as you suggested and will get replacement needle. As for the float height may be more tricky, it’s a frankenbike so non standard carb. It’s got TK stamped on the side but finding one that matches on the web is proving to be troublesome, but yes new float needle to begin.

Anyone know of any TK carb suppliers in AKL (preferably the shore but not essential) where I might be able to take it in to get it ID’d. Cheers

Hey mate I have a few standard carbs in the garage if you want to try them. Located in Otorohanga but I'm up in Auckland from time to time. Also have a stock pipe but with the baffle knocked out.

[globe]

Hey mate I have a few standard carbs in the garage if you want to try them. Located in Otorohanga but I'm up in Auckland from time to time. Also have a stock pipe but with the baffle knocked out.

Cheers mate, I'm going to give the O ring upgrade (LOL) and adjust the float again if not i'll be knocking on your door for sure. I often head through Otorohanga in winter heading backwards and forwards between the mountain so that may work out too, cheers I'll send you a PM

[Akzle]

, sharing is caring so I'm told.

not gonorrhea

[globe]

So after a bit of a break from the mighty GN, back into it.

Did a bit of research and it looked as though the white plastic washer on the needle goes below the e clip accorded to the parts cats. Swapped it over this morning and it ran fine through to half throttle then nothing, No acceleration just sat there. Occasionally it made a low popping sound but generally nothing until i backed off the throttle, then fine again. Did a plug chop (on the stand albeit) at WOT and it came out black so that suggests running rich in the top end. What I don't understand though is that moving the needle up (by swapping over the plastic washer thats about 2-3mm thick) richens it up considerably and this eliminated the flat spot at 1/4 throttle I had before I moved this. Hows that work? Is this suggesting lean out the main needle or jet and get a bigger pilot jet?

HT lead and coil are fine as I have replaced them.

:brick:

Thinking of getting a new (wrecker) original carb, or sending it to a mechanic, sigh....

[globe]

The really frustrating thing is that it was running fine before I cleaned the carb even if it was stalling now and again at idle when warm.....so the jets mustve been ok at some point, maybe I damaged something when cleaning it?

[globe]

The other odd thing is that I can't make the engine stumble with the a/f screw when turning in (leaning as it is on engine side) but can when I wind it out to about 3 turns

[oldiebutagoody]

So after a bit of a break from the mighty GN, back into it.

Did a bit of research and it looked as though the white plastic washer on the needle goes below the e clip accorded to the parts cats. Swapped it over this morning and it ran fine through to half throttle then nothing, No acceleration just sat there. Occasionally it made a low popping sound but generally nothing until i backed off the throttle, then fine again. Did a plug chop (on the stand albeit) at WOT and it came out black so that suggests running rich in the top end. What I don't understand though is that moving the needle up (by swapping over the plastic washer thats about 2-3mm thick) richens it up considerably and this eliminated the flat spot at 1/4 throttle I had before I moved this. Hows that work? Is this suggesting lean out the main needle or jet and get a bigger pilot jet?

HT lead and coil are fine as I have replaced them.

:brick:

Thinking of getting a new (wrecker) original carb, or sending it to a mechanic, sigh....

Every carb (90% suzukis) I have ever been into has had the white plastic spring retaining washer on top of the needle, above the clip.

How many clip grooves have you on your needle? Have you a small steel washer below the e clip on the needle?

If you still have a fuel leak then your float needle seat is not sealing. It could be hard seat rubber (try soaking just the float needle in brake fluid overnight), crap between the rubber and the valve seat, float height set wrong, float needle jamming in the housing (try polishing the inside of the housing with battery dril/cotton bud/autosol.)

When you cleaned the carb what did you use to clean it? Did you get it on the rubber of the float needle? See where I am going with this?

Photos would definitely help.

[globe]

Every carb (90% suzukis) I have ever been into has had the white plastic spring retaining washer on top of the needle, above the clip.

How many clip grooves have you on your needle? Have you a small steel washer below the e clip on the needle?



5 clip grooves, at the current setting, e clip is on top notch, white washer under steel washer on top, that gives a flat spot at 1/2 throttle ish, and WOT. From 1/2 to WOT feels like it lacks power. The setting before I had e clip on middle notch, white and steel under, they were the symptoms in my last post. Prior to this white washer and steel on top and middle notch.



If you still have a fuel leak then your float needle seat is not sealing. It could be hard seat rubber (try soaking just the float needle in brake fluid overnight), crap between the rubber and the valve seat, float height set wrong, float needle jamming in the housing (try polishing the inside of the housing with battery dril/cotton bud/autosol.)

When you cleaned the carb what did you use to clean it? Did you get it on the rubber of the float needle? See where I am going with this?



Fuel leak solved cheers. The washer around the fuel jet had perished and i replaced, problem solved.



Photos would definitely help.

Photos of anything in particular ?

Cheers

[oldiebutagoody]

Yeah my gut feeling is that you have assembled the needle washers in the wrong sequence.

try assembling with the small steel washer UNDER the e clip, e clip in the 1st notch down from the top, white plastic washer ON TOP of the e clip.

being a CV carb, you will note the white plastic washer has a ring on it to locate the long spring under the carb cap. That spring regulates the fluttering of the slide under vaccum and if it is not located on that washer there is no balancing pressure on the top of the slide. If you have that white washer UNDER the e clip I am wondering how exactly you have it sitting?

EDIT: This is all from memory, so I am admitting you could well have a plastic washer UNDER the e clip, but there shouls be a notched plastic washer ON TOP also.

[globe]

OK, had another look at the exploded carb diagram and turns out I was getting my ideas from elsewhere. Reset with the white washer on top, the steel one underneath and took it for a spin, runs lovely on everything 50% onwards. Still a bit "boggy" in the 1/4 to 50% range.

That was with the e clip on the middle notch

[Akzle]

.



Photos of anything in particular ?

Cheers

your mitti's tits

[globe]

Hopefully this photo will help. This is the needle assembly taken apart. From bottom to top around the needle I now have it in the following order

1. (Steel washer)
E Clip
3. Plastic washer
2. Spring
4. Plastic holder

Before I had number 3 the thick white washer below the e Clip.

Cheers

[oldiebutagoody]

Hopefully this photo will help. This is the needle assembly taken apart. From bottom to top around the needle I now have it in the following order

1. (Steel washer)
E Clip
3. Plastic washer
2. Spring
4. Plastic holder

Before I had number 3 the thick white washer below the e Clip.

Cheers

Okay, looking at 1/4 to 1/2 throttle area now to get rid of the boggy feeling. That is where the needle clip setting is having its effect. You need to lean it out, so take the e clip up to the second ring down from top. If its better but not quite right move it right up to the top. It won't affect idle, so for the moment leave the idle mixture screw alone until you have 1/4 to 1/2 throttle sorted.

Then perform the idle mixture adjustment if it bogs down taking off from a standstill such as at lights when the engine has warmed up. There is a small transition stage between idle circuit and needle movement which if either or both are too rich can make it bog taking off from standstill, so the trick is to get needle setting right, then the idle mixture using the correct adjustment process one at a time otherwise you will get confused and chase your tail again.

[globe]

Okay, looking at 1/4 to 1/2 throttle area now to get rid of the boggy feeling. That is where the needle clip setting is having its effect. You need to lean it out, so take the e clip up to the second ring down from top. If its better but not quite right move it right up to the top. It won't affect idle, so for the moment leave the idle mixture screw alone until you have 1/4 to 1/2 throttle sorted.

Then perform the idle mixture adjustment if it bogs down taking off from a standstill such as at lights when the engine has warmed up. There is a small transition stage between idle circuit and needle movement which if either or both are too rich can make it bog taking off from standstill, so the trick is to get needle setting right, then the idle mixture using the correct adjustment process one at a time otherwise you will get confused and chase your tail again.

Good one thanks,what I have found is that moving the needle also seems to affect the response throughout the range, is that normal? For example when I had the white washer on the wrong side it was WOT that was causing the problems and 1/4 to half was OK, doesnt seem to follow the logic I have read everywhere and the good people on here are telling me, cheers

[oldiebutagoody]

Good one thanks,what I have found is that moving the needle also seems to affect the response throughout the range, is that normal? For example when I had the white washer on the wrong side it was WOT that was causing the problems and 1/4 to half was OK, doesnt seem to follow the logic I have read everywhere and the good people on here are telling me, cheers

Ignore symptoms, could be another issue interfering with correct operation. From experience I can tell you where your issue lies and the above stated process is how to negotiate your way out of your problem. Everything to do with carbs is a negotiation, a trade off. There is no perfect, only settings that will give acceptable performance depending on intended use.

Get one thing sorted at a time, make one change only at a time, otherwise; which twiddle that you just did made the thing run better/worse?