First time poppin' into the Stihl thread over here for an issue I'm having with my flat top 066. Love this saw. Rebuilt it with pieces and parts over the course of three years after rescuing it as a nasty carcass from a flooded basement. It flat out screams and usually runs better than I ever figured it would, except...
Every now and again after I've been cutting for a while and it's nice and warmed up it'll act like the timing has become way advanced after a shutdown when I try to restart..., as in wants to yank my arm off when I try to pull it over if I can even pull it over.
Almost acts like it's bound up or has developed ungodly compression from somewhere but will pull over fine if I just go slowly as opposed to pulling it like I'm starting it.
Coil hasn't moved. Gap is good. Flywheel key is intact. All that stuff seems to be in order. Really has me scratching my head when it happens and usually means the end of cutting with it for the day. Try it the next day and it pulls over and starts normally and may or may not exhibit the problem in essentially the same cutting conditions as the day before.
My theory is that just enough fuel is somehow pooling in the case/cylinder and creating ridiculous compression. but if I pull the plug and pull it over I don't get the usual spew out the plug hole like I should if it was flooded. The plug isn't saturated either.
The one thing I haven't tried yet is to pull the plug wire to see if it still happens with no spark. If it does, I could rule out any timing peculiarities. I've also considered hydro-lock as a possibility but always thought that was more of a tank/carb/fuel delivery issue.
TIA for any input.
