Hi Everyone,
Long time lurker, first time poster. I like puzzles and complicated things...
I have this 2F0-2059xx motor that I was told it was a junk yard motor. This past weekend I had this buttoned up to one of my frames and was able to get it to fire up but never satisfactory. It felt like the timing was off, I would get a back fire and felt like the left cylinder was not holding as well as the other. It would take 20 kicks to get a good start but it never idled and spat fire. I also determined that the Previous Owner had burnt their PMA before, they pilfered the ATU so that was never on there before. Also, the Cam Chain was extremely loose.
Now after tearing down I noticed there was a flat spot circled in one of the pictures, on both cylinders? How did this happen right outside where the Intake valve is supposed to chamber and detonate? I also noticed bad wear on the chain guard and the plastic pieces are gone, you can see the chain wear. Some wear on the cylinders but I can't tell if anything serious down there yet.
I turned the motor over with the kick pedal and was able to snag the last photos, now i can't get the pistons to come back up but then realized I have the chain off. I will need to reread the manual and research the forums again.
Please give me your feedback and let me know if you see something that I may not. I took the valves off and spun them on a drill but think I am thinking about opting to get new valves anyway. One of the valve retainer springs came undone after i pulled the valves, everything else looked normal. Will take more pics of the valves later.
I anticipate having to bore out the cylinders and likely have to get some larger pistons, rings too. Should look further and do anything with the crank?