OS FS 20 four stroke engine, test run.

Prop 9"x 6", fuel is four stroke straight, glow plug is a short reach (should have an OS four stroke plug fitted, but did not have one to hand). Handy blue plaster cast! Started easily by my manky hand, couple of flicks with the choke and away she went. Engine runs well and turns the prop with ease. Quite surprising the power from this little four stroke.