low revs judder/stepper motor?

[smithyboy64]

hello all,just took my chim out for a run and it seems to be very juddery on low revs as if going to run out of petrol but goes fine when the pedals down,stepper motor needs cleaning .praps.any suggestions?

[miketvr]

You could also try cleaning the gunge that collects around the throttle butterfly. This affects what's known as the base idle.

If you remove the stepper motor to clean it be very careful on retightening as the body is a fairly weak plastic and easily fractures, as I found out to my cost. Just a pinch more than finger tight.

It could also be ignition problems such as a plug lead or plug.

With fuel injection systems it can be one of a couple of dozen other reasons, but it's worth checking the above out first.

Mike

[smithyboy64]

nice one thanks.

[smithyboy64]

cleaned the stepper motor ,lot better now,thanks.but a bit of a nightmare to restart,eventually she started after many fretting minutes.is this usually the case,anyone know?