Broken ms650

[isaaccarlson]

Got an ms650 that ate a circlip. Chunks of piston in the air filter, carb, muffler, and crankcase. The wrist pin looks blue and will have to be pressed out. Not sure if the crank is ok, because the rod bearing is stiff and feels grabby.

will a 660 crank fit? Looking to rebuild and run if it's worth it. It looks like a grenade went off in there.

The cylinder has no markings on it and the remaining circlip looks highly suspect. Probably rebuilt once before.

 

[jacob j.]

660 crank is a direct replacement - go OEM if you can. If you suspect the cylinder is aftermarket then it would likely be worth finding an OEM 660 replacement and then going
with a Meteor piston kit.

 

[dall]

660 crank is a direct replacement - go OEM if you can. If you suspect the cylinder is aftermarket then it would likely be worth finding an OEM 660 replacement and then going
with a Meteor piston kit.

i didnt think they made a aftermarket 650 cylinder just replaced with the 660
650 are hard to find but run good

 

[isaaccarlson]

Do I need a flywheel puller or can I use the rappy-tap-tap method?

 

[NPKenny]

Looking to rebuild and run if it's worth it.

You could go the other way of you are inclined. I have been on the lookout for case halves for a while. I’m willing to buy or trade.

I strictly avoid the Chinese parts for these saws, which does make rebuilding very expensive without a large stash of parts.

 

[NPKenny]

Do I need a flywheel puller or can I use the rappy-tap-tap method?

Use a knocker and tap it off. I built a puller, but the knocker and a few taps works better.

 

[isaaccarlson]

Use a knocker and tap it off. I built a puller, but the knocker and a few taps works better.

Even with the plastic flywheel?

 

[isaaccarlson]

You could go the other way of you are inclined. I have been on the lookout for case halves for a while. I’m willing to buy or trade.

I strictly avoid the Chinese parts for these saws, which does make rebuilding very expensive without a large stash of parts.

I'd prefer to stay oem, but at 1k for parts, its easier to buy a whole new saw. I have been keeping my eyes open for a bigger saw for milling and bucking big logs. This one landed in my lap today, so I figure I might as well see what I can get out of it.

I don't even know what to charge for parts if I go that route. Not sure what I'd trade for either.

 

[NPKenny]

Even with the plastic flywheel?

Yes. Don’t hit the flywheel. Hit the crank with a nut or knocker threaded over the threads. The inner portion of the poly flywheel is metal.

 

[isaaccarlson]

What do you guys think of reusing this cylinder? Not a lot of scratching, but the bottom of the intake got hammered by the circlip. Maybe .150" down from the edge of the port. Not sure how much timing it would bump if I cleaned most of it up.

 

[isaaccarlson]

Nevermind. The transfer bridges are bowed out. Pretty sure this jug is toast.

 

[jacob j.]

Here's a pretty good looking used 660 cylinder: https://www.ebay.com/itm/194421376252

 

[Maintenance Chief]

What do you guys think of reusing this cylinder? Not a lot of scratching, but the bottom of the intake got hammered by the circlip. Maybe .150" down from the edge of the port. Not sure how much timing it would bump if I cleaned most of it up.

I thought the 650 had open ports?