Husky 562 flywheel key sheared

[fdhamlin]

My saw is a 2012 with EL44 carb. Last year it sheared the key on the flywheel. As a fix I filed the old key out and fitted a piece of #10 solid copper wire, as it is supposed to be only for alignment (timing).
Used it all summer. In the fall it got hard to start. Spark & compression looks good and fuel is there This spring I tried it again and got a big kickback, enough to shear my copper wire.
Now as I set the flywheel in place aligned with the key slot the magnets appear to be about 90 degrees advanced from the ignition module at TDC.
Can't imagine the crank is somehow twisted Any ideas?
Fred

 

[huskihl]

My saw is a 2012 with EL44 carb. Last year it sheared the key on the flywheel. As a fix I filed the old key out and fitted a piece of #10 solid copper wire, as it is supposed to be only for alignment (timing).
Used it all summer. In the fall it got hard to start. Spark & compression looks good and fuel is there This spring I tried it again and got a big kickback, enough to shear my copper wire.
Now as I set the flywheel in place aligned with the key slot the magnets appear to be about 90 degrees advanced from the ignition module at TDC.
Can't imagine the crank is somehow twisted Any ideas?
Fred

The coil/magnet relationship just needs to be consistent. The coil advances/retards timing as needed according to the current demands.

I’d remove your wire and lap the fw to the crank with valve lapping compound. Clean both and reassemble

 

[fdhamlin]

I think found a picture to answer my question. The key slot appears to be oriented correctly.
So it seems, my question is how is ignition timing set by the coil circuitry?
And what are the symptoms of a failed (or failing) timing circuit?

I did find a description of Stihl's M-tronic system. It appears quite similar to Autotune.
As it supplies both spark and DC power for the electronics but saw no other detail.

As compared to my Stihl 250 the 562 is much further advanced. Maybe twice as far at TDC.
Of course the 250 is NOT M-tronic!

Fred

 

[Wonkydonkey]

Your fw moved abit and when you tried to start it, it kicked like a mule/mfker and moved some more..
you need to do what sausage fingers says and refit clean (no grease or oil) and tighten to torque Spec.. It’s i'mportant.to get it close to oem timings

it’s the coil madgic bits that let the angry pixies out at the cleaver time. Which are far to cleaver for me..
But I’m sure if you look at how a coil works on the interwebs, it will explain enough, its just mathematical fast, and there is always more than one way to do the same thing, ie let the pixies out Slower/later and or sooner, remember they are constantly fast where as the engine is the variable part.

 

[fdhamlin]

It's all good now. Sad to say but it was way flooded. The carb had been mis-assembled. Took it apart and reassembled it as per IPL
While carb was off I pulled muffler as well and dried it all out. Before I put it back together it got a 1/2 tsp of mix into the crankcase and it fired right up. My was that loud!
Still can't figure out why it sheared the key in the first place. Cast in aluminum key can't be the best option so I'm calling it good.
Plug went from black to tan after a 5 minute run (obviously had to re-calibrate it's self.

 

[huskyboy]

It's all good now. Sad to say but it was way flooded. The carb had been mis-assembled. Took it apart and reassembled it as per IPL
While carb was off I pulled muffler as well and dried it all out. Before I put it back together it got a 1/2 tsp of mix into the crankcase and it fired right up. My was that loud!
Still can't figure out why it sheared the key in the first place. Cast in aluminum key can't be the best option so I'm calling it good.
Plug went from black to tan after a 5 minute run (obviously had to re-calibrate it's self.

Flywheel nut was probably too loose. I always torque them to the factory spec. Which is about 18-20 ft lb on that saw I believe.

 

[fdhamlin]

I always tighten with impact driver! That is, after seating flywheel and seating it with a drift punch and lead hammer with a plastic face.











Ii

 

[huskyboy]

I would recommend a torque wrench. I wouldn’t use a impact for tightening anything on a saw. Only use it removing the clutch and flywheel nuts. Just my opinion. I’ve f’d up stuff using a impact to tighten things on a saw before.

 

[Wonkydonkey]

Thanks for letting us know.
there are some nuts & bolts more important than others the torque wrench is for checking it’s correct, I don’t have a small torque so I probably over tighten.
But I will say I’ve not done a 200t flywheel up enough before, I was lucky to clean it up and lift the key a bit to line it back up, you only do this once