I Purchased this engine off of RCU several months ago, but I forgot what engine it is. I think that is an OS 1.08 FSR ring engine. the only markings I can locate on the engine is on the side BX-1 and under one of the mounting lugs is either FR, FRI or FR1, the I or 1 (What ever it is) actually looks like a Colon (The Punctuation mark one, not the digestive tract one!) made with two verticle lines, instead of two dots, thus the confusion as to what it really is. Anyway, here is the question part of the post. This engine doesn't seem to have much compression, as I can hear leaking through the carb as I turn the prop. Can I just replace the ring only, then re-break in the engine, or do I need to replace the Piston, Cylinder and Ring?? any help, hints or ideas would be greatly appreciated. I have added some pics to help in the identification of the engine..

Thanks again, Craig.