little gas it dies

[89blaster89]

hey i got this little 83 honda xr 80 and i got it running near perfect, i just made a velocity tube for it and that helped alot, but it seems when its idling if i just give it a tiny bit of gas it will die but if i give it alot then it will rev up fine whats the problem here?

EDIT: just remembered there's a honda section, mods feel free to move

 

[Braaaptor]

Might have an air leak in the intake tract, somewhere between the carb and the head. Check your O rings on both sides of the rubber manifold, and be sure the manifold itself isn't cracked or split.

Also, an intake valve set too tightly will cause this problem. Check your valve lash. It should be. 004-.005" intake, .005-.006" exhaust. Any tighter and you'll have problems.

Just a couple suggestions. Also be sure your pilot jet is 100% clean, and turn the airscrew in slightly 1/4 turn at a time and see how it responds) if you are running a pod or other kind of clamp-on air filter.

 

[89blaster89]

i fixed it for the most part, i played with the air screw, it also doesent do it when its fully warmed up

 

[Blaaster]

When fitting a velocity tube to an intake bear in mind that the air flow changes.

The air closest to the wall will be slowed by friction resulting in the air closest to the centre travelling faster, to maintain the same volume.

This is usually the reason settings or jets have to be changed to compensate for the difference in speed of the air flow.