Have run about 0.5 galon through my new trx 3.3 engine. Was working fine before untila while ago.

The problem is the idle. When i rev the engine up the revs stay up for about 3-4 seconds before going down to idle. (This is not a servo problem i have ensured the servo returns to neutral position.).
When i rev higher- above half throttle the engine revs stay up longer, maybe about 5-6 seconds. Sometimes it takes over 10 seconds for the engine to return to idle revs.

The engine never used to do this. Until the guy at the local hobby shop rebuilt the carb after some fuel had dried and blocked up in there, but has got worse since then.


Thanks in advance to any replies.

Info: engine trx 3.3
Car: Traxxas Jato 3.3
Engine Age: 0.5 galon
Car age: 2.5 galon