testing cyl, right now have just picked up tester i dont now what the compression should test on this motor model is a 115ETL78C lost all power on lower right cylinder also would it be possible to change rings or just one piston if bad thank you
What's the compression on all four cylinders with the plugs out ??
125 lbs would be normal for a factory-fresh engine. I'd pull the right head and see if the head gasket is blown on the bottom right cyl. It is permissible to replace just one piston. Once apart, you might as well put in 4 new ringsets. No point in having one of the other old ringsets go bad 6 months after you just had it apart.