Stihl 064 Broken Flywheel Fin

[Jayboy]

I have a Stihl 064AV with fairly low hours and in great shape. It has a broken flywheel fin. I've been reading on the forum here for a while trying to determine if I'm better off leaving it as is or breaking the fin off on the opposite side.

There seems to be responses saying that it won't matter. Others have said that if there is a fin directly across then break it to match (which there is in this case a fin directly across).

I'm hoping to have the saw for many years so please let me know what would be the best way to go in your opinion?


Just joined the forum and want to say thanks in advance!
I've got a couple beauties I really am enjoying researching on here:
Husky 266XP
Stihl 064AV

 

[mbrick]

I don't have any personal experience here but I would vote to break off one on the opposite side if you can without causing additional damage. It has to be better than knowing it is statically unbalanced?

 

[av8or3]

I wouldn’t break it off. I vote to leave it alone.

 

[Tobystihl]

Flywheels are initially balanced by drilling, maybe this is an option?

 

[kyle.kipple]

I’ve got a broken fin on my 066. Have put several tanks in it after building it and I have not had any issues. I have no abnormal vibrations. I wouldn’t see it causing a short term problem. If it ever causes a problem it would be premature bearing failure in the future if anything.


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[TheTone]

I had a homeowner Stihl, don't remember what model, with one broken fin. I broke off the opposite one and then ground the remaining metal on each one to match as best I could eyeball it. worked fine. Might have worked OK if left alone, but it just seemed that at chainsaw rpm balance was critical.

 

[Jacob J.]

I've seen landing saws run for ten years or more with a fin or fins broken off of the flywheel. As long maintenance on the machine is good otherwise, one missing fin doesn't really matter all that much.

 

[rupedoggy]

The fins provide ample cooling for the machine. I used to work at a tire shop where static balancing was done. We always did a three point balance as one or two point balance would tend to "roll" at certain speeds. Later dynamic balance machines took care of this. But back on point, I think the 036 has about 36 fins (3x12). If you can break of two more in an even space around the flywheel it will not vibrate and will last just as long on the bearings. This is not always possible but usually is. I have done this on numerous flywheels and had no problems with cooling or balance. If you live in the desert and cut in 112* heat it may be a problem but so might heat stroke.

 

[Jayboy]

Thanks for your opinions everyone. I decided to take the fin off directly across 180 deg from it and filed both down to match. I guess on the plus side maybe it'll help with acceleration every so slightly.

I know what you're saying with regards to taking 3 fins off in total to balance. This was more difficult to attempt since the other 2 fins would have been different sizes.. So i went with the 2 that were the same size at 180.

 

[pbilly]

a single broken fin wont make any difference in it at all