This is the 044 that I loaned out to a coworker, which cured me of ever loaning out a nice saw again. Don't know what he fed it...I left him with full tanks and not much work left to do, but it came back with a toasted crank bearing and a smeared piston. Felt like my dog died.
It then sat partially disassembled in a box in the tool chest for a couple years. I bought a bailey's 046 big bore cylinder kit, did a little grinding on the ports to (IMO) improve shape and flow, ground the case to clearance the 54mm piston, spent a fortune on crank bearings and peripherals, and it's been quite a ripper ever since. The piston change from 50mm 044 stock to 54mm 046 big bore results in 82ccs displacement now.
I just went out to see if maybe something had lodged in the high speed jet...started it up, warmed it, checked low speed, then while checking full throttle for 4-stroking or overspeed, it oversped, lost spark and croaked. I'm thinking there's an ignition issue afoot, but am also not ruling out a lean issue because it went from the saw I know and love, to one that oversped for a bit, to the no-spark croak. Still hard compression so no worries there yet.
Anyway, I have OEM rubbers on the way (fuel, impulse) and an imposter boot since OEM are either $$ or hard to come by, and now am thinking I'll get a coil coming too.
Also bought an open-box cs-590 from Ebay for $365 so will see how that one does. They apparently do well with a carb adjustment, cylinder base gasket delete, and a bit of muffler roto-rooting, all of which is allegedly expedient.
There are some fun threads on the OPE forum and arboristsite about 046 to 044 conversions. If my 046 Chineseum big bore piston/cylinder take a dump, if someone on here has a used OEM 046 cylinder I'd like to give that one a shot on my 044 carcass with a new Meteor piston...
Need to have more than one big Frankensaw on hand for when this happens. Will sniff around for another toasted candidate for rebuilding.