I rescued this from the trash man It's a BVM200FE, not BMV. Wouldn't start. Got gas and spark. Low compression, about 40 lbs. I squirted some oil in the cylinder, and compression went up to 80 lbs. Reinstalled the spark plug, and started on first pull. Ran poorly, but ran. I assume I need a piston ring, as oil boosted the compression. I do have the parts list, but no service manual. My question is, if the cylinder is worn also, are the new replacement rings big enough to cover the extra distance created by wear? I don't see any listing for oversize rings. Do they need to be fitted, as in how much end gap in the ring, or is what you have is it? I do not have any specs on ring gap or bore diameter to go by. I was just hoping this would work as a drop in replacement.