Probably a stupid question, but I'm guessing there isn't another way to boost compression without lowering the jug?
Pop-up pistons. Two-piece heads. Eliminating the base gasket (which is lowering the jug). Cutting the squish band does two major things at once when it is combined with lowering the jug. It shrinks the combustion chamber and increases the effective stroke of the engine. That is, the distance from TDC to exhaust port opening.
glad to help! That round was the 1st cut with the 661, had to go at it from both sides to get threw that 40" maple. I have a 36" Tsumara for the saw also, but I was waiting to get 5 or 6 tanks threw it, before I put it on. Someone told me it was a good idea, to wait until I get a few tanks on the saw, before putting on a bigger bar and working the saw.hard. I am not sure if it matters? What do you think? A 28" buried deep has to work it pretty good? Or a 36" with the tip hanging out a few inches? I went back to the pile yesterday to cut, and brought my camera to take pics and make a vid, but forgot my SD card at home, DUH!! I had fun non the less!!
I think special break-in rituals are kinda silly, but that's just me and my opinion. . I would avoid extended idling, frequent or extended high-rpm operations, and lugging the engine, other than that, use the saw as you would normally. If the tip isn't buried, you probably would work the saw less than having the 28" buried. 36" bar with sharp 3/8" chain isn't going to hurt that machine one bit. New or otherwise.
I think Randy just said "BINGO". Randy, did you check the factory WOT before porting? Also, have you checked the WOT after the 200psi? Just curious if it changed. I know my factory 660 4-stroked well around 12800. After you ported it, with the same fuel and ambient conditions, it seemed to raise the WOT 4-stroking an additional 1000rpms! Best I remember Porsche said his factory 661 tached out at 13200.