Trophy 160 steppermotor/ rev problem

Hello all,

When I accelerate hard in my Trophy, usually taking it in 2nd or 3rd to the rev limit, I'll find that the idle revs then rise to 1000 -1200. I reset the stepper motor and it is fine. But what can cause this? anything serious, it is always hard acceleration that will cause this. Needs cleaning? Or a symptom of a more serious issue?

Regards
John L

Possibly it's the throttle vane that is sticking. Pull the air filter hose off and open and close the throttle by hand (engine off) and see if it always returns to closed.

The plastic bodied throttles are a bugger for this. Metal 52mm less so.

Other than that, a split hose or failure / sooting up of the IACV or even snagging of the throttle cable, it has a much longer run than in most cars.

When the engine is hot, disconnect the IACV/stepper motor.
What does it idle at? Should be around 800. Plug it back in and it should go up to 875.

Sometimes if the base idle speed is wrong the stepper motor keeps trying to make adjustments to the idle speed when it shouldn't.

Hi all,

I had a look about today in the engine bay and decided to service it - spark plugs and air filter clean. Also cleaned the throttle plate with some cleaner, so we'll see what happens in the future!

John