hi all. i have an os 120 fs surpass non-pumped motor. apparently it is an older version with a choke flap (as per another member here, not my knowledge as i am very new to this aspect of the hobby)
I believe this plane sat for a while. I'm unaware if the engine was ran during the winter or if after run was used after its last flight. I was told it did fly last before the winter. My concern is that the prop is extremely hard to turn by hand. I have not tried with the electric starter yet. There is NO plug in the engine either so its not building compression. I belive there is an abnormal amount of constant resistance somewhere in the engine. There is "free" spin at all. Even if i try to snap the prop in either direction, it will only continue in its movement for a degree or 2 thats it. It won't even make 1/8th of revolution if you snap the prop. So I removed the head hoping that the problem was somewhere in the valve train, but its not. With the head off the engine, it still is extremely tight to turn. Once I removed the crank case cover, I noticed alot of what looks like rubber debris inside the case. Mostly behind the rod. Im unsure if it is rubber or not. Unfortunately I do not have the correct size tools to pull the cone and prop off, I will try to get them this week. That is my next move I think. Here are some pics of what I see. What are your thoughts? Where would you go with this?