Ummm, well, I really don't know a lot about the 262, I've never even ported one. I think they're 48mm bore by 34mm stroke? The problem I see with really low exhausts on the older saws with a big case, and large but short transfers, is that the transfer pressure is not high enough to overcome the exiting exhaust flow. You'll probably have a saw with a very wide happy range, and lots of grunt.(which is what I have been trying to get from the 562 without much success). Also, I don't think that the 262s piston skirt is wide enough to go as wide with the ex port as what I normally do. In what way is the 261s piston different than the 262?
The dished piston would not be the best way to lower compression, it will hinder good scavenging. Just machine some material out of the combustion chamber.
I will be putting a wheel on the next batch of 562s that I do, and get some good, hard numbers. I also have a few more ideas for improvement. Has anybody tried exhaust side fingers in these saws?!
