HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
ganja772006

fed up with no good inforamtion

36 posts in this topic

got 2000 yahama yz426 with white bros series exhaust. ....valves and carb rejetted by dealership....it runs good with choke on but when its off it dies...got a lil bog and hestation to it ....bascailly wont stay runnin without choke .....was told i have an air boot leak or rubber joints for the carb needs to be replaced....any help would be highly appreaicated....HELP before i junk this amazing machine

Share this post


Link to post
Share on other sites

Did it stall before the dealership worked on it?

Is the idle turned waaay down?

What is the current jetting?

More info will net you more info.

Share this post


Link to post
Share on other sites

It's normal for a carbureted engine to act lean and not idle for a time between when the choke is pushed in and when it finally reaches operating temperature. With everything right, it may be as much as 10 minutes before it will idle correctly. Are the guys at the shop telling you that they can't make it idle, either?

Share this post


Link to post
Share on other sites

my CRF did that and it was a plugged pilot. cleaned it out with some carb spray and ran great. This could be a possibility.

Share this post


Link to post
Share on other sites
My guess... the metal plate in the carb slide is in upside down.
That would normally have the opposite effect, making it richer at low throttle openings. BUT, you could be onto something, too. The seal in the slide plate could be damaged or missing, or the plate could be cracked.

Share this post


Link to post
Share on other sites
That would normally have the opposite effect, making it richer at low throttle openings. BUT, you could be onto something, too. The seal in the slide plate could be damaged or missing, or the plate could be cracked.

Gray, when my 00 426 was almost new to me, I pulled the carb as completely apart as I could... mostly because I like doing stuff like that, and partly because I was either re-jetting or cleaning it. I managed to put the plate in the slide upside-down, because it actually looks correct installed that way. The bike would only run with the choke pulled out, and ran horribly. Push the choke in and it would die almost instantly. I freaked out, posted on TT, then went back out and flipped the plate around after someone suggested it. Bike fixed!

Share this post


Link to post
Share on other sites
got 2000 yahama yz426 with white bros series exhaust. ....valves and carb rejetted by dealership....it runs good with choke on but when its off it dies...got a lil bog and hestation to it ....bascailly wont stay runnin without choke .....was told i have an air boot leak or rubber joints for the carb needs to be replaced....any help would be highly appreaicated....HELP before i junk this amazing machine

This is the way the dealer gave it back to you?

Did they try to fix it and found the air leak and told you to fix it?

Seems strange for them to claim they jetted something if it wasn't running right. What you described sounds like a clogged pilot circuit, but you'd think they would have cleaned that while they were in there. It could also be an air leak like they say.

If they gave it back to you like this, it probably still isn't jetted correctly. They may have even tried to compensate with the jetting for an air leak and now it's way off from where it should be. Or even worse, they tried compensating for a clogged pilot circuit instead of cleaning it, but I kinda doubt that.

Did this bike sit for a long time after you got it back from the dealer? If it did, it could have clogged up since you got it back from them.

Do you have a hanging idle when it's running? When you hit the throttle, does the RPM's hang high, then finally come down and it dies?

Did you turn your idle adjustment screw(black knob) all the way in trying to keep the idle up?

How many turns out on the pilot/fuel screw?

Do you have a receipt that says what size jets they installed?

Do a search for 'FCR hanging idle' or 'FCR pilot circuit', you will find a ton of information on fixing pilot circuits and air leaks. I just recently had to go through this and it drove me insane till I finally fixed it. Searching through all the info on this site sent me in the right direction to find the problem. :ride:

Share this post


Link to post
Share on other sites

thanks everyone ....gona take the carb apart and see if the slide cover is on upside down.....clean the carb once again and try that....im thinkin the cover is messed up ...gona replace the rubber intake too cuz it does got a lil leak ....but im new to this thumper talk ......its been real helpful!!!!! thanks everyone!!!:ride::thumbsup::lol:

Share this post


Link to post
Share on other sites
thanks everyone ....gona take the carb apart and see if the slide cover is on upside down.....clean the carb once again and try that....im thinkin the cover is messed up ...gona replace the rubber intake too cuz it does got a lil leak ....but im new to this thumper talk ......its been real helpful!!!!! thanks everyone!!!:ride::thumbsup::lol:

Just check it before you disassemble the carb... the flat side goes down.

Share this post


Link to post
Share on other sites

hey cowboyona426.....you just saved me a few bucks cuz i found the problem the throttle slide was upside and i put ti like u say and it runs like a bat outta hell.....thanks buddy so much for losing 300 bucks on 20 yr old mechanic at the yahama dealer...what a dumbass

Share this post


Link to post
Share on other sites

Thanks cowboyona426.....finally solved the problem after three months of headache never wouldve thought anything bout the slide i took it off and behold the 20 yr old dumbass that worked at the yahama dealer mess my shit up.....youre a lifesaver....what i owe ya??

Share this post


Link to post
Share on other sites
hey cowboyona426.....you just saved me a few bucks cuz i found the problem the throttle slide was upside and i put ti like u say and it runs like a bat outta hell.....thanks buddy so much for losing 300 bucks on 20 yr old mechanic at the yahama dealer...what a dumbass

Wow, that's just sad, you should have taken the carb back to them and showed them before you fixed it. I'm glad I can work on my own stuff, I wouldn't have thought a dealer mechanic would have made that mistake. But then I was having a hard time getting my head around them giving you a non running bike after they were supposed to have fixed it, I guess I shouldn't be surprised. :lol:

Glad you got it fixed though! :ride:

Share this post


Link to post
Share on other sites

The problem is solved and anyone whoever ....listen to cowboyona426 hes pretty damn smart.....saved me a trip and a few bucks ....see ya everyone im gona go out and play!!!!

Share this post


Link to post
Share on other sites

IT WAS A 20 year old kid that worked on it....i even called and told them you guys got a dumbass workin for ya......lol

Share this post


Link to post
Share on other sites
IT WAS A 20 year old kid that worked on it....i even called and told them you guys got a dumbass workin for ya......lol

Nice! :ride::lol:

Share this post


Link to post
Share on other sites

It's an easy mistake to make. The throttle plate looks for all the world logically as if it should go in rounded side down, but it doesn't.

As far as Cowboy being smart, he's not too bad, but it's one of those things that's probably better if you don't ask how he knows about that particular problem. :lol::ride:

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0