Help Diagnosing this MS461 Failure.

[csmitty]

So I need a bit of help with this one. I had been watching it on ebay and it ended up pretty cheap. Guess I didn't pay enough attention to the pics. But it looks like some catastrophic clutch drum explosion or something happened. Case is cracked and gouged in that area. Clutch looks like it got hot as well. You can also see how hot the case got, thats not dirt.

Pulling the clutch off. All kinds of mess.

It rotates fine and I can't feel a crank bearing failure.

Piston shows some discoloration on the exhaust side and is incredibly gunky under the muffler.

Intake is fine and looking through the spark plug hole I don't see any scoring above the exhaust port.

Then the underside of the brake handle is melted. I'm assuming since the exhaust is pointed straight at it.

Anyone have any thoughts? Never seen anything like this. My fault for not studying the pics closer but debating what to do with it. Used parts are hard to come by and expensive new for the 461. Missing the tank and starter housing as well as covers. Probably would need a case half as well. My first dabble into the 461's and maybe I should have just stuck to 460s. I guess if the cylinder and piston are ok I could atleast part it out and get my money back or make a few bucks.

 

[CR888]

Looks like a 'smoking hot' deal you got!lol Pitty there is not many used parts around for 461's yet....a 460 would have been easier to do cheap. Is that a brake band melted into the plastics?

 

[Khntr85]

Looks like it was run with the chain brake on.... I just rebuilt a ms250 that had that happen.... it can cause a lot of parts to fail when ran like that...usually the worm gear is melted away too...

 

[blsnelling]

That damage is from corrosion. Palm tree sap will do that. It can eat all the way through the case.

 

[blsnelling]

 

[Andyshine77]

The clutch has some blue to it so it definitely got too hot at some point. We also see some corrosion, as Brad said likely from sap. That saw was road had and put away wet.

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[csmitty]

Looks like a 'smoking hot' deal you got!lol Pitty there is not many used parts around for 461's yet....a 460 would have been easier to do cheap. Is that a brake band melted into the plastics?

Yea, my first rebuild was a 460. Probably wasn't cheap as I ended up just using mostly OEM stuff anyways. Though it wasn't bad. Bearings/seals/gaskets/lines etc. Meteor piston though. Now I have most of the tools so need to flip a few saws to pay for them Plus I was looking for a dedicated cheap Lewis Winch saw.

Looks like it was run with the chain brake on.... I just rebuilt a ms250 that had that happen.... it can cause a lot of parts to fail when ran like that...usually the worm gear is melted away too...

Kind of what I was leaning towards as well. The shoe material was worn away and only way I can think that the clutch showed that much discoloration from heat.

That damage is from corrosion. Palm tree sap will do that. It can eat all the way through the case.

Interesting, hadn't thought of that but makes sense. It seemed like it was fine magnesium shavings combined with oil. Maybe thats why my right side half is pretty fubar'd.

 

[csmitty]

The clutch has some blue to it so it definitely got too hot at some point. We also see some corrosion, as Brad said likely from sap. That saw was road had and put away wet.

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Yea, that was a pretty good give away. I just couldn't figure out what would make it get that hot, other than a chain brake engaged and someone couldn't figure out why it wasn't turning. Then maybe it eventually did and just kept getting hotter with friction. So yea, this guy was pretty abused. I even see some water in the case, but that could have come from something after as well.

 

[csmitty]

So after further inspection it seems like this is actually a MS441. That's one funky carb set up. So unless I can find some used parts cheap will likely part it out.