A couple of years ago, I had an engine that just wasn't putting out what I thought it should. It started fine, idled and transitioned well, and flew well. But it's top end rpms weren't what I thought they should be. I took it apart, and found a ring gap of about .012". Specs call for a ring gap on these size engines of around .003" as optimum, (which by the way is a very tiny gap). So, I ordered a Frank Bowman ring for it, and installed it at Frank's recommended zero gap. I ran it rich for one tank, and then leaned it out and check the rpms. It gained over 800 rpms!!

The Ryobi has a poor design for the ring pin. The pin that keeps the ring from rotating takes up the whole ring land, instead of taking only half as do most other two stroke engines. This makes for a ring, brand new, that necessarily has a very wide gap. When you install a Frank Bowman ring in a Ryobi, you either tap or grind down the pin so that it is only half as deep as the ring land. Then his ring is fashioned so the part of it fits over the pin, providing a gap of zero, or near zero. This helps power tremendously on the Ryobi!!

BTW, thanks for the reports and all the hard work to obtain them. Good work! Now try a Bowman ring!!

AV8TOR