Chainsaw Repair

I'm only guessing about the rpm's. On all three saws, 038, 029 and 660, if I pushed a little too hard they would start 4-stroking or kinda flooding, I'd let up a little and let them clear out and go again. Just a good light steady push. Now at least I thought that was what was happening.

I took all the guts, cages, out of the mufflers, opened the outlet up on the 29 an 38. Had to heat the crimp with a torch on the 29 to get it apart, then heated it to crimp back.I put a new Walbro WJ-76-1 and a 98cc kit on the 660. The 98cc kit was probably a mistake and may change it back when I check for carbon. I also got a new Cross cylinder kit on the shelf I could put on, one of them MMWS cylinders. Even if it's better it wont cure what I'm doing wrong. I think a tach may at the least tell me where I'm at with the rpm's, my ear don't seem to be doing it.
Thanks