Had this CS8000 for 3 or 4 yrs. Bought it from original owner's son or nephew or something. Came with 36" Echo bar and chain. It is a low sn gray colored saw. I doubt if it had 5 or 6 hours on it though when I got it. I have fell and bucked up the big end of several good sized oaks with it. Also got me a 24" b&c setup for it. So I have put probably 10 -15 hrs on it. Not the fastest , but a lot of grunt. I never have been able to get it to consistently run smooth though. Been through carb. Always run ethanol free 91 octane gas and Stihl full synthetic mix at 50:1. Passes pressure and vac test and blows 155psi on Snap On compression gauge. FSM calls for 135psi. Anyway, I was cutting with it the other day and had the 24" bar burried and was about to get it pinched. Just as I eased off the throttle so I could drop a poly wedge in above it , it backfires and started running backwards. I had to look at chain a second time to believe it. I killed it pronto. So, I pull it out and fuel it up and go again. It starts up fine and runs a few more minutes and then backfires again and dies. So, I pull flywheel and check key. Looks fine. Put it back together and same thing. Try to start it and it just backfires out exhaust. Thing is it seems to have plenty of spark. Just not at the right time. The FSM makes some mention of the magnets in the flywheel being too close to each other or something like that, that can throw the timing off. I have correct air gap. I don't think end of crank is twisted. Runs very true. This saw has always started cold after 4 or 5 pulls and usually one or 2 when warm. BUT, it has never been a good drop start saw. It has always felt like it wanted to kick back if I didn't put it on the ground and stick my toe through the handle. Is this just bad cdi/coil or what? They are made together on this saw. FSM tells how to check timing with a light on a running saw but mine is not. Even if it was I am not sure how they expect you to start it with flywheel exposed. Roll start maybe?
CS8000 Ignition trouble
- Thread starter alfbolin
- Start date
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I have no way to test it but my best guess is that the module`s trigger has stuck too far advanced and is firing at a point far before 20 - 29degrees BTDC, this would cause the engine to run backwards. If you like , retard the flywheel some, about a full key width clockwise and see if it will run correctly. Not a cure but more of a test and then you would know that a new module would be the cure.
Should I use anything to help hold it without a key? Just thinking if it still kicks back it might get way off before I get test complete. I would say you are pretty close at a key width. FSM shows it to be like .490 distance at outer edge of flywheel.
The nut torqued down will hold the flywheel in place, the key does not, it`s just an alignment aid for spark timing. The tight dry fit between the flywheel and crank is all that is needed.
