Tuners…Help!

1981 IT465 won’t start. It ran fine for the shop that built it, and for me 1

week ago on our maiden voyage. It has new bore, piston , rings and seals.

Once I figured it out, it starts within a few kicks no problem. Idles fine,

accelerates well ( no stumbles etc ), plug color a nice chocolate brown

after tooling around a grassy field ( it wasn’t a chop throttle test ).

Now, it will fire on 2 or 3 kicks, but will die when I crack the throttle or

turn off the choke. It will backfire at times when kicking, but no kick-backs

at all. I swapped the CDI unit thinking that it was the problem, but get the

same result with the 2nd one ( not new ). Spark is a nice blue/white.

Any ideas would be much appreciated. I was all set to go riding Friday, but

ran into this condition and am out of things to try. HELP!

Has the carb been cleaned?

I ran carb cleaner and compressed air through the air screw circuit, but

haven't removed the carb yet. Next step is to take it apart and check float

level and the other circuits. I have a good fuel filter on it, and it ran fine

a week ago. Just need some help understanding what to look for.

Also, make sure you have good fuel flow from the tank. Check for floaties (debris/coagulated oil) inside the tank that could impede flow. I have run into situations where the bike has sat for long periods of time and the gas has evaporated and left a sheen of two-stroke oil deposited on the bottom of the float bowl and/or gas tank. When new gas is introduced, the old oil sheen breaks loose and gets stuck in the main jet or petcock screen. It doesn't re-mix with the gas, it stays in a gel like form and clogs things. :p

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