[Lash]

I am rebuilding an open rocker fs60 and there are no manuals from OS that give any information on this. The problem I am having is the cam timing. There is a mark (dot) on the cam drive itself but there is no mark on the crank. How are these lined up? I have used top dead center on the crank and the dot straight up. It seems to run very well but I have no idea if this is correct.

[floyd]

RE: TIMING AN OLD O.S. F.S.60
When you look at the ring gear, you will see the ends of the three bolts that hold it onto the timing assembly. Between two of those bolts will be a small depressed dot. When the piston is at Top Dead Center, that dot goes straight up. You can remove the cover at the rear of the assembly so that you can put a finger on the screw and keep the assembly from turning when you install the assembly into the crankcase.

This is from another web site. I think you have it correct. Cheers floyd

[Lash]

That is how I did it so I guess all is good. I'm used to Saitos so this is new to me. Thanks for the quick reply!

[RAMJET]

the screw in the back of the cam assembly behind the aluminum cap is a left handed thread , be sure to turn it in the correct direction when removing , another unique to this engine feature is having to remove the cylinder so you can slide the wrist pin through a hole in the rear side of the engine casting . the rest is pretty straight forward. cheers Roger

[Lash]

There is no hole in the engine casting on my engine. You just unbolt the front and the crank pulls out. Then the piston comes straight up and out. These are so cool on an old time airplane. I have scratch built a Ringmaster for it and they are perfec together.

[williame3590]

I still fly them on several models. You should check out the nostalgia forum.

Bill

[kip51035]

A quick check to see if your valve timing is right:

1. Remove the glow plug and put a toothpick or small straw in the hole.
2. use this to set the piston at top dead centre on the cross over stroke.
3. Both valves should be open the same amount.
4. Rock the crank back and forth at top dead centre to check that the valves are even.