So I did replace the piston rings. I was getting a little blow-by in the same spot on both sides.
I want to get rid of my Accu-products Dcomp anyways. Gonna get the electric start this winter so I don't need a weak spot. I've removed it before for cleaning. I dont think it is leaking though. No soot in the threads and not through the clean valve after cleaning and not using the valve for a rid and checking it again. No blow-by on the valve.
but I've always suspected that the style or any pressure release would have to lend itself to at least slightly less compression since the chamber is larger for part of the stroke.
I admittedly have a BS car compression tester. before replacing the rings I was getting 120psi and after replacing, only 125. I later read that possibly a car Comp tester is inadequate for testing a dirt bike. There is not enough turnover speed and volume to fill the larger 1/4 hose that is used.
The new rings felt harder to kick over after a heat cycle. But my bike never seems hard to kick like people talk about. I can pretty much sit down and kick it. I am 240lbs though. Might be different if i was 170lbs like "MX ridier". I don't even bother using the compression release on the trails. Could be my compression is just fine now. My buddy has a "dirt bike" comp tester. So that is the next step I guess.
If you know about the Accu-producks style valve. Could I send my cylinder in to get the "sleeve" pulled out and plugged on the cylinder wall and outside of the cylinder, or just plug the wall with an aluminum plug and re nickasil the cylinder?
Say I am only getting 125PSI comp test. I'll figure it out over the winter, but should I try going to a 7 heat range to get rid of my sooty plugs? I run non ethanol 100 octane fuel. Or should I just not bother?
as a side note, besides the plug I had to (and failed too) scrape a layer of buildup off the piston. Never got it all off...
I've only ever fouled 1 plug and I did have the carb way to rich. but would running a 7 help keep the plug or even the piston cleaner? If either of those are even a concern? Would I still be okay to open it up on the straights with adequate jetting and 100 octane race fuel. (BTW I run 32:1 Castor)
to answer your question I have a Wisco 2 ring stock size piston and Millennium coated the cylinder about 20 rides ago. 3 hour ride average mostly low speed 1st 2nd gear trails, with occasional higher speed roads.
I will say a lot of this is pure curiosity, tinkering, fun, and dialing it in. Other than my idle at times the bike runs like a champ. Even if it's not putting out every HP possible, Its way more powerful than my buddies yz250. It starts cold on 2-3 kicks, and warm (i can get quick or lazy sometimes, but if i try) starts on 1 solid kick.
So My issues are nothing like some peoples. I just like learning, researching and absorbing info on things I'm interested in. Looking forward to your responses. Thanks for your time.