MS461 Damaged Cylinder - Afterlife?

[Axotopia]

Just curious ... is this MS461 cylinder toast or is it salvageable?

Got this from someone who is tossing it away, figure I could use it to practice grinding. But if it is salvageable, I might as well turn it into a porting project just for kicks.

The portion above the exhaust port and combustion chamber looks undamaged, and most of the long gouges are at the bottom of the transfer and intake.

I assume most of the combustion would have vented thru the exhaust by the time the piston rings reaches the top of the transfer ports; the two nicks may compromise things a little, but maybe not too detrimental to operations I hope.

As for the deep gouges on the bottom of the transfer ports and the intake, i don't know how that affects the mechanics of the operations, so maybe somebody can educate me on that.

Any feedback would be greatly appreciated. Thanks!


Intake - gouge on the bottom


Exhaust - no damage


Transfer - Gouge on bottom with nicks on top


Transfer - gouge on bottom of one port

 

[cuinrearview]

That damage would surely affect the transfer timing. How much? I'm not sure. I think it would run after some careful cleaning and filing. I'm sure some with more experience modifying cylinders than me will chime in.

 

[dmb2613]

junk in my opinion

 

[Chainsaw Jim]

If you're only wanting to experiment and not sell it on a saw then you're good to go. Just clean up the roughness and smooth the edges with a little bit of fine grit by hand. Those little gouges on the transfers won't change the timing...and won't catch the rings if the sharpness is taken off the edges with the sandpaper.

 

[user 122190]

Hard to tell from the pictures. Thumb nail is the best way to tell, IMO.

These are cheap -->

If you think it is possible, go at it. Only when it is clean and you slip a ring into the cylinder and measure the gap at various depths, will you know for sure.

 

[Axotopia]

Thanks for the feedback. Sounds like the cylinder may still be functional, so think I would go ahead and practice on the free messed-up cylinder instead of the one on my saw. I am sure I will be making dumb mistakes along the way as a rookie, so may as well do it on the cheap. BTW, I like the idea of using the honing bit to clean up the bore.

For the gouges, is there any benefits or perils using a J-B Weld Highheat to fill in the void? It doesn't sound like performance is going to be noticeably compromised by the damage at the transfer ports, my feeling is to leave it alone and concentrate efforts on ports.

 

[user 122190]

From my reading porting can be quite the science. Still I'd give it a try if I had a free cylinder. Lots can be learned, in success or failure. Unfortunately only upon installing the ported cylinder can you know of any degree of success.

Thanks for the feedback. Sounds like the cylinder may still be functional, so think I would go ahead and practice on the free messed-up cylinder instead of the one on my saw. I am sure I will be making dumb mistakes along the way as a rookie, so may as well do it on the cheap. BTW, I like the idea of using the honing bit to clean up the bore.

For the gouges, is there any benefits or perils using a J-B Weld Highheat to fill in the void? It doesn't sound like performance is going to be noticeably compromised by the damage at the transfer ports, my feeling is to leave it alone and concentrate efforts on ports.

 

[ericm979]

The gouges are too small to affect port timing much but it looks like they're past the plating and into aluminium. The plating around them might peel up in use. JB weld won't fix the gouges and might come loose while running. I'd use it to practice grinding on ports but would not run it. There are companies that can repair and replate a damaged cylinder like that but it probably costs more than a new OEM cylinder.

The A. Graham Bell Two Stroke Tuning book is good.

 

[Axotopia]

The gouges are too small to affect port timing much but it looks like they're past the plating and into aluminium. The plating around them might peel up in use. JB weld won't fix the gouges and might come loose while running. I'd use it to practice grinding on ports but would not run it. There are companies that can repair and replate a damaged cylinder like that but it probably costs more than a new OEM cylinder.
The A. Graham Bell Two Stroke Tuning book is good.

Thanks for pointing me to the right direction with Graham Bell's book. BTW, like to share another interesting resource I just came across today, it's Gordon Jennings' Two-stroke Tuner's Handbook (http://www.amrca.com/tech/tuners.pdf) .... definitely way over my head technical as well but great information on how the engine works and porting considerations.
As with the Nikasil flaking, that looks like a very real possibility. Think you are right, may be cheaper to just use the cylinder for practice.

From my reading porting can be quite the science. Still I'd give it a try if I had a free cylinder. Lots can be learned, in success or failure. Unfortunately only upon installing the ported cylinder can you know of any degree of success.

Starting to realize there's a lot of technical considerations than just grinding away. Good point on getting started.

Thanks!

 

[drf255]

I’m guessing you cleaned it up already? What’s with the rough sanding by the base on the Fly/PTO sides?

Get some small diamond balls in fine finish and also some scotchbrite in drums and sheets. Hit all the high spots with the ball, then hone the jug with WD40 and scotchbrite.

As Jim said, I wouldn’t sell a saw to someone with that cylinder without full disclosure, but it should be fine to run.

Hi temp JB isn’t a good idea. It will burn off and/or chip off.

Happy porting.