MS 310 with Defective Flywheel Magnets

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Joel SImpson

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Just a heads up since I didn't find much searching for this. I purchase a lightly used "AS IS" MS310 as a limbing and small bucking saw backup with no ignition. Replaced coil, plug - no spark. Rung out wiring using my old 029 as a guide and everything looked good. Tried removing kill wire from coil. Only piece left seemed to be the flywheel magnets. I then compared the lifting strength of my flywheel from the 20 yr old 029 against the flywheel from the newer MS310. A non-scientific test showed that the 029 flywheel had about 20 times the strength, so I replaced the MS310 flywheel with the 029 and BINGO - nice strong spark and starting saw. I had read this is a very rare situation (bad flywheel magnets) so I had almost ruled it out when troubleshooting. Wanted to share this in case it might help someone.
 
The older 2100cd Husqvarna’s with the SEM ignitions we’re prone to the flywheel weights coming loose. We would epoxy them.
 
Its rare that the flywheel magnets loose magnetism and even rarer the polarity changes but a few of us that have been around chainsaw repair long enough have experienced it.

Yep...had it happen a couple times......damn hard to diagnose too.....one thing I always try is reducing the air gap from 0.012" down to 0.006-7"...may help...may not....there was as service bulletin on the late model 70E Jonsereds about hard starting that stated that.
 
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