Funny you ask, I finally got around to running it on Saturday. I didn't have any big wood to buck, so I threw a 28" bar on it (with an 8 pin) to cut 24" white oak, which did an okay job of loading the saw with a little pressure on it. I threw the tach on it with the 28" b&c, it was turning right around 13.4k-13.5k at WOT out of the wood. A little high for my comfort, but I used it anyway since I knew it would drop down in the cut. I made about 20 cuts with it and then shut it down at WOT so I could later read the plug.
I pulled the spark plug yesterday to see how it looked, it appeared a little leaner than I'd like (although not too bad), so I'll be reaming out the jet a little more before she goes out for another workout. Hopefully this will drop the revs down a hair at the same time. 13.5k wasn't enough to really frighten me, but I'd feel pretty safe if it was around 13.2k or so. Once I get the plug looking nice, I'll try to report back as to what I finally ended up with on the main jet sizing.
Regarding the timing, I think it depends on the coil. The 272 coil I had on hand dropped right in and the timing was exactly where it was with the factory 2005 EPA FW/coil. I would not expect this to always be the case with all 272 coils, so check before and after if someone out there is considering doing this change. Also noteworthy, I didn't have to notch the case for the 272 coil, as I feared.
I have to tell you this thing is is pretty LOUD WFO after doing the muffler mod, and boy does it scream now!!! You can really feel it in your chest when she's doing her thing. It's a totally different saw now after doing these mods. I haven't compared it to the 880 yet, but my guess is it will walk the (stock) 880 now by a significant margin. It really is hard to believe this is the same saw and that it woke up this much with a few cheap and simple mods...
I have a a couple of projects I still need to get to first, but if I have the time (and I never seem to), I'd like to drop the jug, do some porting, and advance the timing a few degrees. Not that it really needs more power (it's pretty impressive as it sits), but you know how it goes. :hmm3grin2orange: