MS660 siezed, cylinder salvageable?

[jstare]

I picked up a siezed ms660 locally and I've started to strip it down for a rebuild. I'd like to re-use the cylinder with a meteor piston if the cylinder is salvageable.

The cylinder seems to have avoided any aluminum transfer off the piston. Only a couple small scratches. My only concern is in the top of the jug, it seems to be rough. But it looks to me like rough casting and not damage. Any insight to the cause of the seizure would be great.

I have limited experience so I wanted to ask the experts here.

 

[singinwoodwackr]

Hard to tell from the pics how bad…and where…the scoring is.
looks like a ring shattered and all the little pieces rattled around for some time
just going by what happened I’d say replace P&C, bearings/seals and do a thorough inspection of the rod bearing. If ring parts got into that bearing you’ll likely need a crank as well.
good luck

 

[ballisticdoughnut]

Look at the crank bearings closely. Looks like it may have had a cage come apart.

 

[trains]

circlip failed ? , its taken some chunks out of the jug, not sure if its usable again.

was this an after market top end that has let go ?

look at the cage bearing for the bottom of the conrod, and the case bearings will need a good flush out at minimum, and a close inspection and possible replacement if their cages have suffered damage from what ever travelled around causing that damage.

 

[singinwoodwackr]

Look at the crank bearings closely. Looks like it may have had a cage come apart.

Ah, yes…looks like most of the rings are still there, so…
circlip doesn’t usually do that much damage…unless he ran the thing rattling away until it finally froze up.

 

[Mad Professor]

Hard metal parts got loose inside P/C assy. Looks like many made it up and down several times inside. You need to clean up cylinder and take better pictures. I'd be wary of crankshaft as well.

That is carnage.

 

[Yukon Stihl]

Yes inspect the bottom end carefully.
I am waiting for bearings for a 359 that the big bearing went on the crank.The main bearings on that crank don't roll free anymore.Stuff got in them and damaged them you can't see any damage but you can feel it when you roll the bearing on your finger.

 

[trains]

looks like circlip sized gouges on the piston.
ear from after market clip fails, rattles around causing mayhem.
nice crack on the skirt too.

 

[cookies]

Intake port side has chunks out of the plating and deep scratches, i'd get the full meteor kit if you can't go oem. That case needs splitting and bearings/seals replaced after that much metal went through it..also scrub out the muffler really really well.

 

[jstare]

So I took apart a few more things today. I hadn't taken the wrist pin bearing out before. But when I did it crumbled into pieces. Its likely a smaller chunk had come off previously. I'll just get a whole top end for it and not bother with the existing top end.

 

[Yukon Stihl]

If you are going OEM top end split the case and do the bearings and seals.
If you are going to gamble with aftermarket then it should still be split and bearings done, but you never know everything may hold together for years if you don't.

 

[Gabriel1982]

I picked up a siezed ms660 locally and I've started to strip it down for a rebuild. I'd like to re-use the cylinder with a meteor piston if the cylinder is salvageable.

The cylinder seems to have avoided any aluminum transfer off the piston. Only a couple small scratches. My only concern is in the top of the jug, it seems to be rough. But it looks to me like rough casting and not damage. Any insight to the cause of the seizure would be great.

I have limited experience so I wanted to ask the experts here.

Sad to see a chainsaw destroyed this bad. Cylinders are electroplated,thickness from my knowledge is very thin. Haven't measured it but any visible scratch will render the cylinder to scrap metal bucket! You could "insist" on putting a new piston in same cylinder but it will not run for long! Unless you're selling it to next sucker...
If you want a rebuild saw, get a ms660 manual ,split the chainsaw ,measure/check all parts ,replace ALL weared/destroyed parts with aftermarket or OEM parts,reasemble correctly and enjoy a good saw for some time!