[sm=confused.gif]It looks like I ruined my B&S 34cc engine. It was running nicely, but suddenly stopped after about 10 minutes of running (at various throttles), and was very hard to turn over. When I took it apart I found small metal chunks inside the crankcase, and a couple of gouges in the cylinder wall.[sm=omg_smile.gif]

Before running it I filled it with 10W40 oil and the temperature outside was over 50 degrees. I let the engine run for several minutes to warm up before throttling up. It ran much better since drilling out the jet but still went a little lean at wide open throttle. Max RPMs I got it to were 6000, which doesn't seem like over-revving to me. I guess it was the oil I used.[sm=confused.gif]

If I were to try one of these again I would use only the recommended B&S synthetic oil! The owners manual states that using 30 weight oil below 50 degrees can cause cylinder bore damage! The manual says that the synthetic oil is good for any temerature.

It's too bad because it was running beautifully before it seized up![sm=cry_smile.gif]

Jim