Throttle stop screw???

[Made2Fade]

Does anyone know what the throttle stop screw does on the YS 61 ST2 engine? Its the black screw with a spring on it, located on the top of the needle valve assembly.
Thanks
Lee

[jimbob]

It would set the maximum closed point of the barrel normally.

[Made2Fade]

Hi mate, so could that affect the idle?
Lee

[jimbob]

Nope - just the point at which the barrel will stop closing.
The ST4 and OS heli engines dont have them at all, and you just set the idle and closed position using the ATV.
The throttle stop screw is purely mechanical and nothing to do with mixture.

If screwed in too much, you wont be able to close the barrel enough to get a slow idle - thats about all.

FYI http://www.yspower.co.jp/pdf/61ST-2e.pdf

[Made2Fade]

Cheers bud, got the manual already but it doesnt really mention anything about the stop screw. Stripped the engine today and cant find a thing wrong with it. Its brand new really. Ive now run out of ideas about the engine dying when left idling.
Lee

[robgt]

Is the glowplug ok?
If you use silicon to seal the exhaust to the engine, a little might have got back in to the plug - not enough to blow it, but enough to make it run poorly, especially at idle.
Just thought I'd toss that into the pot
I know nothing of YS engines currently!
Cheers,
Rob

[Made2Fade]

Ive changed the plug out to make sure. Ive also pulled the engine today. I cleaned/checked it. The engine is brand new, no marks/scratches on the internals. It seemed to be very clean and no rubbish in the carb or anything. Im planning on fitting it tonight and ill try it tomorrow. Will let yaz know how i get on but this has got me stumped for now. I dont use silicon either. I usually just use a gasket. These engines are also new to me but ive heard they are good,keep a tune and have bags of power.
Lee

[jimbob]

I must admit, idling wasnt one of the issues with my YS.... let us know how you get on.

Did you check all the fuel tube?

[Made2Fade]

Ill change the whole lot out tommorrow also and let yaz know how i get on.
Thanks for your help so far though guys.
Lee