Thanks for all the detail, Cory. All that intel is in the hip pocket now as I move forward with this. Turned out to be a pretty dirty saw underneath everything that could otherwise be cleaned with an air nozzle. Got it cleaned up enough to see how the engine comes out of the housing now and hope to do that today.
I did discover some marks on what otherwise looks like a new piston that I can only attribute to a piece of carbon from somewhere. I'll pull the cylinder to see if there's anything floating around in there after I do a cursory leak check of just the case. Seals
look new.
Not sure what the torque spec for the cylinder nuts/studs is, but all four were loose in my mental torque calculator..., as in a 1/16th ~ 1/8th of a turn. Seemed like a lot to me. Was also a little surprised at how easily the flywheel nut and clutch drum nut and clutch came off. Thought I was going to have a real fight on my hands removing the clutch without the tool, but it spun right off just using a pair of Stihl carb studs in two of the three holes and a long handled scrench between em to turn it. And once the clutch was off I obviously realized how the oil pump works and checked that off as a possible case leak source. Now
those screws were
seriously torqued down!
As for the carb and intake leak possibilities, I'll check all those details carefully and seal accordingly as things go back together. The whole intake assembly actually seemed quite secure considering the saw was running like the carb could have been loose. Bolts were nice and snug there.
I'm pretty impressed with this saw all the way around so far. A solid piece o' machinery that doesn't really seem to have any obvious weak spots. This particular one belongs to a customer but I have a pretty nice one too. Just haven't gotten too deep into my own Homelite acquisitions yet -- with this being my first actual foray into the XL series. I actually have several in various stages of needing between a little TLC..., and a lot! I'll get to em one o' these days. This one is a newer one than any I have and I'm going with '88 according to my understanding of the 9 digit numbering?
Anyway, thanks again for the input. It's very much appreciated.