Jonsered 621 flywheel

[Ludwig457]

Have a running 621 in good shape, and a decent backup 621 for parts. Today's task was to replace the damaged flywheel.

First thing, saw runs and sees wood daily. Thing is the flywheel has 2 broken fins. Remove primary flywheel, install replacement flywheel from my parts saw and lose my spark. Reinstall original wheel and spark returns.

Both wheels are identical (same model number, shape, design, number of fins, etc lol? Although there are slight differences on the underside

I have never had the opportunity/luxury of a backup parts saw. And am curious/puzzled, what am I missing? I look forward to learning, or possibly relearning this quandary (or rookie mistake more likely)


Any advice is appreciated

Cheers

 

[L34]

Are the magnets good?
How strong of pull if you move a screwdriver towards them?

 

[ShadSwaz]

I recently watch a video from afleet where he had an issue fly wheels on a 2 piece ignition where the part numbers were the same but there was a difference in the revision number of the flywheel. One was version 1 and one was 5 I believe. Maybe some weird change over period part.

 

[KASH]

Run it with the two broken fins .80 percent of the points equipped saws I have worked on have had broken fins.they were broken by guys jamming a screw driver in the fins removing the flywheel nut.
Kash

 

[Ludwig457]

Thank you for the replies, I've been running with broken fins.

621 in the wood and I feel good lol? Thx all