H35 Smokes...

[longlongtimeago]

Original 3.5 hp on my 1970 Rupp Scrambler has really started smoking. Seems worst at and just off idle.

Should I assume it's the rings? If you agree, think I can get away with just a hone and rings? Really don't want to go thru the hassle of boring it . Not sure if I can even get oversize parts anymore...

 

[creia]

I would start with measuring the compression. Then, before you do or buy anything you will need to open it up (Is there lots of oil laying on top of the piston?) and inspect the bore for scoring. Then take good (precise) bore measurements at top, middle , and bottom and see how badly it is worn oversize, tapered, or out-of-round (or all three!) If the bore is shot, new (standard size) rings and honing will not accomplish anything.
Michael

 

[longlongtimeago]

Thanks for your advice. I'm really asking what to expect after I pull it apart, BEFORE I pull it apart.

In general do guys have any luck just re-ringing these things or is it common that I will find the bore to be shot.