This is a used engine that I rebuilt. I was very lucky to find a NIP ABC P/L set for it; it was originally ringed. I also installed new bearings. The rear bearing is an oddball Y-17 (17x32x8) that Boca stocks. I also put in a new rod and gaskets.

It's a good strong engine. It turned within 22rpm of my OS .61FSR which did 12,964 with the stock muffler. I ran the ST with a new Silent muffler.

Temp: 56°
Powermaster GMA 5/22
K&B 1L plug
APC 11x7
12,942 w/Silent muffler
1.39hp
7.93lbs. static thrust

David