Hi Dave;

I have an old YS 120 SF (first ones) engine, it was running ok until now. At a given moment the engine (between flights) the engine did not start. I did everything imaginable to the tank, lines and hi needle with no results. I did have to check the regulator, seem to be clean.

The engine only starts at full throttle, and dies if lower than half throttle. The regulator is not working (apparently). The tank has good pressure even 1 minute after the engine dies.

Regulator is immaculately clean; the holes have been flushed with a syringe and some fuel line. The silicone parts are ok and the gasket seems ok (I know is a trouble some part) the knob on the regulator is toward the front.

Only problem I see is that the plunger once inserted into the regulator body.

Any thoughts?

Alexis

Sorry, my English is not good.