MS 310 with Defective Flywheel Magnets

[Joel SImpson]

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.

 

[madhatte]

Gonna move this one to Chainsaws. You'll likely get more and better discussion over there.

 

[Joel SImpson]

Thanks, I don't know my way around too well yet.

 

[Huskybill]

The older 2100cd Husqvarna’s with the SEM ignitions we’re prone to the flywheel weights coming loose. We would epoxy them.

 

[pioneerguy600]

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.

 

[HarleyT]

Actually, the last US presidential election really ruined quite a few flywheels

 

[Cantdog]

Actually, the last US presidential election really ruined quite a few flywheels

Well.....it certainly did reverse the polarity at least.....

 

[Cantdog]

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.

 

[alexcagle]

I had demolition customer that dropped a Stihl TS800 from an 8th floor high rise once. The magnets on these saws have a set on opposite sides, and the fall caused the flywheels magnets to go haywire.