[SIZE=3][FONT=courier new][COLOR=indigo]I have a OS MAX .61 SF with an OS pump unit on it. I need some information about this engine and the pump unit. First, what size props are recomended?, sencond, best fuel to use?, third, What is the best way to break this engine in?, and last, what is the correct plumping of the pump?
On the last question I have four ports on the pump. They are marked IN, OUT, S, R. The IN and OUT are self explainatory. The S port is hooked to a second port on the carb. Does the R port go to the vent on the fuel tank, or exhaust vent line or both.
I have no instruction mannual for this engine since I bought it at a swap meet, but the engine is very clean inside and out wich leads me to believe it has only has very low run time, if any. probably only a little break in on bench.
I am putting this engine in a CG Super Chipmunk with a pitts style muffler. Any help would be greatly appreciated.