Stihl 041 flywheel nut torque?

[Howard L]

Hi,
I have an '79 041 Farmboss that sat under a roof leak for a couple of months which resulted condensation collecting under the flywheel and under the points/cover. There was a little corrosion and some flakes had shorted out the points. Some light sandpaper on the magnet and a brushing cleaned it up and I put it back together and the saw started right up.

A few days later I took it out to cut a load and after say five 12" log cuts when I let off the gas it quit and I heard and felt what I thought was the crank spinning without the piston. I was relieved to find that it was only the flywheel. The nut had loosened and the flywheel sheared the woodruff key.

So I picked up a couple, put one in and tightened down the nut to what I felt was enough.
I mean I was holding the flywheel with one hand and using a regular 3/8 socket wrench with the other, and being concerned about stripping the threads, holding the wrench fairly close to the socket and giving it a real hard wrist twist.

I got about half way through a cut when I sheared that key!
So I put the other one but this time I pressed it into place with pliers and then on tightening nut held my hand a little further out on the wrench and giving it all I had.

That held ok for the rest of that log, about another 10-15 16" cuts.

But now I'm thinking I should make sure I have that nut torqued to specs.
Anybody know what that should be?
Thanks.

 

[oldmanriver]

Hi,
I have an '79 041 Farmboss that sat under a roof leak for a couple of months which resulted condensation collecting under the flywheel and under the points/cover. There was a little corrosion and some flakes had shorted out the points. Some light sandpaper on the magnet and a brushing cleaned it up and I put it back together and the saw started right up.

A few days later I took it out to cut a load and after say five 12" log cuts when I let off the gas it quit and I heard and felt what I thought was the crank spinning without the piston. I was relieved to find that it was only the flywheel. The nut had loosened and the flywheel sheared the woodruff key.

So I picked up a couple, put one in and tightened down the nut to what I felt was enough.
I mean I was holding the flywheel with one hand and using a regular 3/8 socket wrench with the other, and being concerned about stripping the threads, holding the wrench fairly close to the socket and giving it a real hard wrist twist.

I got about half way through a cut when I sheared that key!
So I put the other one but this time I pressed it into place with pliers and then on tightening nut held my hand a little further out on the wrench and giving it all I had.

That held ok for the rest of that log, about another 10-15 16" cuts.

But now I'm thinking I should make sure I have that nut torqued to specs.
Anybody know what that should be?
Thanks.

tighten to 29.4 Nm (3.0 kpm) is what the book says

 

[Howard L]

Ok!
Felt scary especially the way it kept turning slowly without feeling tighter but it came up ok.
That took it another 3/4 turn anyhow.
I didn't try but 3 kpm is probably as hard as I could have pulled on the small socketl wrench. (8"?)
I've wound a few bolts off lately so I get a little freaked.
Thanks for the help.

 

[oldmanriver]

I done the same thing one time with a 041 FB, after that I just tighten the hell out of the flywheel nut when I'm puting one back on and havent had trouble since. Hope it works out for you and you get her going.