Hi guys, ive just been helpin friend with his ZXR 400 H1 1989, Basically weve cleaned the carbs and set the pilot screws still running a little rich but it still wont return to idle after blippin the throttle, 99% sure its not suckin air only thing we havent checked is float heights aparts from that the carbs are as spec in manual...

Any ideas?....

Thanks,

Peter

Choke mechanism stuck? Throttle return spring fubar?

thunderace wrote:Choke mechanism stuck? Throttle return spring fubar?

sorry thunder race my mistake

Forgot to mention the choke isnt stickin on, the throttle returns all the way on it own force but if i unscrew the idle screw all the way out the revs return to idle instantly but if i change the idle screw so the bike idles smoothly it takes forever to return to idle,

Sorry but ive corrected my mistake haha thanks for your idea tho :)

ive rechecked the pilot screws and they are all correct (2 and 1/4 turns out) i have checked all the float heights aswell all but one were correct or within tolerance i have adjusted the one that was letting too much fuel into the float bowl and its correct now.

Cant think of much more that could be causing this problem, dont think that carb balancing would help it all that much....

Regards, Peter

try turning your airscrew in a bit, to 2 turns on all instead. its getting to much air. sounds like a lean pilot set up.

I know it maybe obvious but check for air leaks? make sure they are seated ok etc..

Thanks for your replys it was sucking in air from where the air box meets the carbs dues to a bodge job lol,
someone had used a poor sealant with incorrect O-rings which they had to chop because they were too small haha quite funny tbh lol

Thank you all for you replys very grateful for the help :)

Regards,

Peter

I have exactly the same issue, been working on an L1 for a while now. When i came to getting it running i got everything sorted except this exact issue.

I wasn't sure what would be causeing it but thanks to reading this thread its given me some ideas.

Cheers Guys

Great forum