combatpilot,

I guess I don't understand why you want to close this thread and start a new one. I would be inclined, if I might give my $.02, to forge ahead with the original topic of the thread and that is ".....ryobi performance modification, analysis and comparison". There already has been a wealth of information collected about what works, what doesn't work, and what might work in the quest to get more out of the Ryobi. Part of the process of discovering what works to improve performance IS the "guess/try/guess again" nature of the work. Just because you've hit some snags doesn't mean you should give up! If you started a new thread it would just create a discontinuity on the subject. Although I haven't done a thorough search on the Ryobi subject I'd bet this thread is one of the longest yet, even though there are only a handfull of contributors so far. It's true that there are a number of off topic posts, which is to be expected, but sometimes those posts spark some interest in other areas that are related to the subject.

If you started a new thread on the same subject what would you call it and how would you relate it to the information that has been collected on this thread?

diceco

BTW I've just completed an analysis, using Gordon Jennings two stroke tuning book, and discovered that for the bifurcated transfer port cylinder, the transfer ports are plenty big enough to give peak power at 7500 rpm but the exhaust port is not. I further determined that the duration number of 150 deg for the exhaust port, that's been mentioned by several, is just right if obtained by raising the top of the port 0.11 inches. This not only gives greater duration but larger area also. In so doing Jennings suggests an elipsoidal shaped port and proper radiusing and chamferring of the edges of the port. I'm looking forward to see what the performance gain really is. Even if one doesn't use the calculations in the book, his general comments on what makes two stroke motors work is very good reading.