Flywheel Testing

Bigbear

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Aside from a sheared key or visible damage, is there any way to test a flywheel on a Stihl saw other than it having a strong attraction to a screwdriver? It would seem a flywheel is essentially bullet proof if properly installed. I am having spark issues and have done all the seemingly necessary tests and gap adjustments, module change out, etc. I also understand ignition modules can test good or bad intermittently.
 
Being the correct flywheel for the model also helps- like the 064/066 series, there are about 30 possible combinations of flywheel and coil for those- assemble a saw from a parts bin and you can have all sorts of headaches finding the correct combination.
Air gap from coil to flywheel can be more particular on certain models.
Spark plug type can be particular- aftermarket sparkplugs with exotic names are crap.

What particular model of Stihl are we talking about?
 
This one is the old standard Stihl 271 Farm Boss. The flywheel is original and I am waiting on an OEM Stihl module. I have precisely changed gap settings with no difference noted. The replacement after-market module is suspect, but I never heard of a way to accurately test a flywheel except on a saw.

Today is the first day of spring in Ohio as you are approaching winter in Zealand, right?
 
Well if approaching Winter is heading into Autumn- then yes, I guess we are.
Water drains down the hole in an opposite direction as well- but a Stihl 271 is still a Stihl 271.

Check integrity and connection of all earth wires. Only use an OEM ignition module on these, part # 1141-400-1307.
Curious- what caused the coil to be replaced from original?
Did the aftermarket coil run for a few weeks, few months and then you arrived at the situation you have now?
 
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