Ms361 flywheel- cracked?

[BuckthornBonnie]

Building up a 361 for a Mennonite farmer out of two he had laying around. Pulled the flywheel to find a sheared integral key and what appears to be a crack. Thoughts?

 

[BuckthornBonnie]

Hard to see from the pics, but it looks like a crack originating near the sheared key. Odd.

 

[Canadian farm boy]

Spray a bit of brake cleaner on the suspect crack and watch it evaporate. If there is indeed a crack the brake clean at the crack will be the last to evaporate.

 

[blsnelling]

I think you might be right. That does look like a hair line crack.

 

[BuckthornBonnie]

I think you might be right. That does look like a hair line crack.

Yep. Darn... hope the other fw is ok. That case has bad bearings so it’s been rubbing.

 

[BuckthornBonnie]

Spray a bit of brake cleaner on the suspect crack and watch it evaporate. If there is indeed a crack the brake clean at the crack will be the last to evaporate.

Will do. I’m pretty sure this thing is Al scrap now.

 

[Cracker Boy]

Spray a bit of brake cleaner on the suspect crack and watch it evaporate. If there is indeed a crack the brake clean at the crack will be the last to evaporate.

Brake kleen good for everything

 

[Cracker Boy]

Will do. I’m pretty sure this thing is Al scrap now.

I have one the keyway is sheared but no cracks if your interested its marked were keyway was and you can see it 25 plus ship and its yours

 

[BuckthornBonnie]

Spray a bit of brake cleaner on the suspect crack and watch it evaporate. If there is indeed a crack the brake clean at the crack will be the last to evaporate.

Good trick... worked. I can also feel it with a screwdriver. It’s scrap. I wonder what would have happened if it released when running.

 

[BuckthornBonnie]

I have one the keyway is sheared but no cracks if your interested its marked were keyway was and you can see it 25 plus ship and its yours

Sweet offer... thanks! I’ll try this other one I have. It’s been flared back a bit due to bad bearings and it’s got a couple missing fins, but it should be ok.

 

[Greenerpastures]

Sweet offer... thanks! I’ll try this other one I have. It’s been flared back a bit due to bad bearings and it’s got a couple missing fins, but it should be ok.

Will a flywheel with missing fins not be terribly off balance.
Just saying, it would be the last thing anyone would want after
investing time on putting her all back together.

Hope all works out though.

Regards, john

 

[BuckthornBonnie]

A fin or two isn’t too bad, usually. This particular fw has two opposing fins cracked off at just about the same place. It’s probably not too far off from balanced.

 

[Greenerpastures]

A fin or two isn’t too bad, usually. This particular fw has two opposing fins cracked off at just about the same place. It’s probably not too far off from balanced.

Thats good news.
Does not look like an overly strong center to begin with.
Any idea as to how the key got sheared, must have been quite
a sudden stop, hope the shaft did not twist in the process.

 

[BuckthornBonnie]

Not sure. There was an impact on that side of the saw and the tank was smashed. He bought both of these saws used from a local shop... one of em never ran well, the other was “ok” but problematic at times.
So far I’ve found impact damage on both, the fw issue, cracked fuel lines on both, stiff impulse lines, bad bearings on one, missing hardware on both ... oh, and a fuel line installed wrong.

 

[BuckthornBonnie]

So I have an “ok” bottom end to build up. The one cylinder is useable. The other has fins missing and possibly more damage. Going with Meteor piston.

 

[Cracker Boy]

Sweet offer... thanks! I’ll try this other one I have. It’s been flared back a bit due to bad bearings and it’s got a couple missing fins, but it should be ok.

This one has no fins missing its oretty clean except the keyway

 

[Greenerpastures]

You have a challenge on your hands, I hope it all works out,
given the condition of both saws, I would not build the owner
one, for when he can wreck genuine stuff, he is likely to come
a cropper again in the near future.
The key way in the above image looks to be at an angle as if it
were pulled against sideways, is there a burr also showing to
the left side of the keyway in the image.

Regards, john

 

[Canadian farm boy]

The ms361 flywheel key is cast into the flywheel bore. I believe in the picture Brian posted what you're seeing is marker showing where the sheared FW key position is.
The FW key isn't what hold the FW in place on the crank. It's only job is to act as FW position locator.
The tapered FW bore and the tapered end of the crank are a friction/pressure type of fit. Once the FW nut is tightened down the FW won't move.

 

[BuckthornBonnie]

You have a challenge on your hands, I hope it all works out,
given the condition of both saws, I would not build the owner
one, for when he can wreck genuine stuff, he is likely to come
a cropper again in the near future.
The key way in the above image looks to be at an angle as if it
were pulled against sideways, is there a burr also showing to
the left side of the keyway in the image.

Regards, john

Yep... it’s why they finally called me I guess. I don’t mind a good challenge as my barn is pretty full of learning experiences at this point lol.

 

[Cracker Boy]

The ms361 flywheel key is cast into the flywheel bore. I believe in the picture Brian posted what you're seeing is marker showing where the sheared FW key position is.
The FW key isn't what hold the FW in place on the crank. It's only job is to act as FW position locator.
The tapered FW bore and the tapered end of the crank are a friction/pressure type of fit. Once the FW nut is tightened down the FW won't move.

Correct amundo my friend