Please help with idle woes!

GoldenMotor.com

Moto

Member
Jan 7, 2012
403
15
18
San Francisco, CA.
I have had my bike for about a month, its been running great during run in and pulls pretty fast. The other day I was going on a ride and pulling back on the throttle a little more than usual, like 3/4 open or more (im still in run in), and it was running really smooth. But when I stopped at a intersecting and pulled in the clutch the engine started really revving, like redlining. Just a high constant unhealthy sounding rpm. When I go to pull out of the intersection and let out the clutch the rpm's drop back to normal and the bike rides the same as before. Now every time I idle it just redlines and makes me scared that the engine is going to implode :(!

Right now im thinking its an air leek, maybe some people have suggestions on how to find it...
Heres my setup:
straight plug engine 66cc
stock intake
dellorto sha 15.15 carb and air filter
Please help!!!!
 

2door

Moderator
Staff member
Sep 15, 2008
16,302
175
63
Littleton, Colorado
This is a classic symptom of an air (vacuum) leak in the induction system. I have no experience with your carburetor so I won't make any recommendations about it but along with checking for leaks make sure your throttle cable is not binding and that the throttle mechanism in the carb is returing to the idle position.
Good luck. Let us know what you find.
Tom
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,837
252
63
up north now
Air filter, carb, intake manifold or "tube", and technically, the porting in the engine. Everything the air/gas goes through before it gets to the piston.

What usually happens is the gasket gets a leak or the carb loosens up.