After replacing bearings and ring in an old ST60, I took it out yesterday to break it in a bit. It fired right up but seized about 30 seconds in. It was plenty rich so I must not have gotten it clean enough. The crank pin is in excellent shape but the rod is tight on it. I thought I’d take it to work where I have a nice Sunnen hone. I figured I’d hone out a touch. Just need to know how much clearance there should be. If it doesn’t work, I’ll try to find a new rod. This is free to try at this point though!
Thanks, Matt