Slight hanging throttle on TTR 90, stumped.

[richep]

Have a Yamaha TTR 90 for my 7 year old and the bike runs great except for one problem. When letting off the throttle, the rpm's barely stay up for like 3 seconds before it goes to idle. It's not bad, but it scares my kid enough that he is uncomfortable riding it. It's always the same amount of time before hitting idle. I put a new throttle cable in along with plenty of freeplay. The slide looks like it is dropping fine by eye. I'm stumped, please help. Had carb apart and cleaned every passage twice.

[richep]

Also, does the needle rest firmly in the main jet when the throttle is returned? Or does the slide hit the idle screw keeping the needle above the main jet opening?

[alexzhere]

sounds like it could possibly be an air leak. while its running try spraying some brake clean or carb clean around different parts of the engine, and see if it changes the idle, if it does you have an air leak and need to replace the gasket

[bman176]

Richen the pilot jet.

[mortiky]

yeah sounds like jetting maybe off a bit..