[tom tilson]

Engine was run low on oil and piston seized. Was able to free it up and it has 55psi comp cold and about 70 with a tablespoon or so of eng oil. I know nothing of the previous history on this engine. Engine is stubborn to crank and needs excessive choking. When it starts, will take full load,but when it idles, may idle a min or two before becoming erratic and then stopping. Carb has been thouroughly cleaned with welch plug and needle removed and all passages punched out, sprayed with carb cleaner and blown out with compressed air, Also new fuel pump membrane installed. Could this be a compression issue, or have I overlooked something on the carb. Plug changed also and Idle adjusted to 2200 with tach????????.PS evidence of some scoring on major thrust side of cylinder.

 

[30yearTech]

Low Compression

Yes, that would be a very good possibility, low compression and the scoring in the cylinder area. The engine may not be producing enough power to run at idle speeds.

 

[tom tilson]

Thanks Ken, I was hoping you would reply.
I went into the engine yesterday and found no damage other than the scoring on the walls about 7/16 wide. It honed out nicely. There was no ring ridge on upper bore. One little bump about 1/4" on the major thrust side of the piston which I smooted off. Not a customer machine and since the piston still fits the bore well, I am going to rering it tomorrow and wondering if the idle problem goes away. Tom