My 461 has been locking up while trying to crank it lately . I can slowly pull it until it frees up .The saw runs fine other than the starting issue. I need to get this figured out because it is quiet painful .
Could be your decomp valve is weak and just the compression is closing it before it fires.
I don't know that the ignition can go bad and still work advanced but not retard at start up like it is supposed to. It is an electronic circuit so you are basically top dead center just pulling the rope and then it advances as it revs up like a car engine or whatever.
As opposed to old 066's etc. , that were like 25 degrees advanced all the time and would rip the meat off your fingers if you got lazy pulling the rope.
Thanks i hardly ever use the decompression valve on this saw but i did while trying to finish the job we were on saturday.
I thought I'd read about flywheel keys shearing of before, letting the whole flywheel turn a bit and sending the timing way out of whack. Something to check, anyhow.
Move control to choke and then pull the starter slow enough not to produce spark but enough to flood the engine, maybe 3 or 4 pulls.
Then move control to I without touching the throttle.
Try starting now. It may take a couple of pulls to start, but is it locking even now or does it start?
In some occasions,usually higher hour saws the bushing in the starter drum will fail causing the starter drum to run eccentric .Because of this the starter pawls will become bound up .Other mechanical causes could be too small of a starter rope or having the drum wound too tight causing the recoil spring to bind up .
Thanks for the advice from everyone. I dropped it off with my dealer first thing this morning . The tec seemed to think it was carbon and not ignition. I also told him to port it and mod the muffler if he had to pull the jug.
Just picked it up this afternoon, he cleaned the decompression valve ,replaced the ignition module from a donor saw and found me a muffler from a larger saw . then tuned the carb. I think the decompression valve was the culprit.
I like to trade and support local business . It has paid off for me , got my saw back the same day and at no charge . I will admit to buying them lunch from time to time.
Sounds like money well spent.