Won’t idle:

[Memy1251]

hey guys, so my first build i ran it and the engine idled flawlessly. For a while, then the bike would no longer idle. When I pull the clutch the RPMS shoot sky high. When I leave the clutch it’s always trying to go like a car placed in “drive”. Any ideas? Thanks guys!

 

[MotorBicycleRacing]

air leak.

 

[Memy1251]

Thanks for your help. I figured that could have been a potential cause, but where do you usually see these sorts of leaks if you don’t mind me asking?

 

[Jimmy Bloodmaker]

you probably have an air leak where the carb meets the intake. it's a normal thing with a new build, i have found in my building of these. little bit of Teflon ( pipe tape) tape will cure it usually. i run a runtong carb, has a plastic gasket in the tube tht connects the carb to the intake, solved all my air leaking problems. lso add a oring inside the carb throat on the back. find one tht fits the lip inside and press the carb on the intake while you tighten it.

 

[Memy1251]

you probably have an air leak where the carb meets the intake. it's a normal thing with a new build, i have found in my building of these. little bit of Teflon ( pipe tape) tape will cure it usually. i run a runtong carb, has a plastic gasket in the tube tht connects the carb to the intake, solved all my air leaking problems. lso add a oring inside the carb throat on the back. find one tht fits the lip inside and press the carb on the intake while you tighten it.

thanks a load, dude! I’m gonna do both those things. Say you don’t layer on the Teflon tape? You just put one little layer?

 

[Jimmy Bloodmaker]

i layer it till it seals. might take a few tries to get the depth perfect. to much and it just slides back, not enough and it doesn't touch all around to seal tight.

 

[Jimmy Bloodmaker]

also check your cable, make sure it's not to tight. use the adjusters to get it so it doesn't lift out of the threaded adjuster, but not so tight it pulls the slide up.