MS660 Seizing Up

[Chainsaw Jim]

I popped off the sprocket and gave it a wiggle and it's really tight. Would the play be there with the clutch still installed?

Yes. But you have to make sure the thing isn't seized up when you are checking. The flywheel side needs checked too.
Regardless what's wrong it needs to come apart, so pulling the cylinder without removing the carb is easy. You remove the handlebar and muffler before you remove the four cylinder bolts. Then you loosen the clamp on the intake and carefully pry the boot off the cylinder. If the cylinder bolts are removed before you take the boot off then the cylinder will likely pop loose and pull away from the boot as you're prying on it.

 

[pepe_silvia]

You should probably pull the carb and have a peek. It could be melted pretty bad and still be perfect looking on the exhaust side. The back side of the cylinder can have damage below where you can see when peeking through the exhaust side.

Getting caught up here....this is bad, right?

 

[fordf150]

Yep. That's bad

 

[fordf150]

Stop right the and do not disassemble any more until you pressure and vac test it

 

[pepe_silvia]

Stop right the and do not disassemble any more until you pressure and vac test it

Ok, should I put it back together for that?

 

[fordf150]

Carb has to be off to do that. Was it checked when the new cylinder was put on?

 

[pepe_silvia]

Carb has to be off to do that. Was it checked when the new cylinder was put on?

I believe it was, but I don't know what the numbers will. I'll ask the guy that did the job.

There's been another development. Just noticed this:


and found this:


I think the piece of the spring was getting lodged between the clutch and the drum.

 

[Chainsaw Jim]

Getting caught up here....this is bad, right?View attachment 479424

Observe the big crack on your intake boot lip on the right side, right at the mounting stud. That's a huge leak.
That boot is just plain hammered.

 

[pepe_silvia]

Observe the big crack on your intake boot lip on the right side, right at the mounting stud. That's a huge leak.
That boot is just plain hammered.

Geez, yeah, I see what you're saying. I'll add that to the list.

 

[Poleman]

Observe

Good eyes Jim.... that sure doesn't help.....
Pull out the metal ring and see how far down the split goes..

 

[tla100]

Bump for a informative thread and great pics!! Keep us posted how it turns out.

 

[Chainsaw Jim]

I'm curious to know what the numbers are on the carb. WJ69? The boot looks jacked up enough to maybe be a poorly done modification.

 

[fordf150]

I'm curious to know what the numbers are on the carb. WJ69? The boot looks jacked up enough to maybe be a poorly done modification.

Good catch on the split.

I see what you mean about poor mod. The boot sure doesn't look like it fits properly.

 

[pepe_silvia]

I'm curious to know what the numbers are on the carb. WJ69? The boot looks jacked up enough to maybe be a poorly done modification.

At work now, but I'll take a look later. I think I've learned my lesson about buying saws from Mexican Flea Markets, now matter how good the price is .

 

[tickhound93]

I wouldn't do a vac test right now. In my opinion this saw needs to be completely disassembled and gone over with a fine tooth comb. While its apart, may as well do crank bearings. This thing needs rebuilt completely. Only way to get piece if mind out of it now. Sometimes a guy doesn't have time or money to do it right the first time, but the second time it fails a guy can afford time and money then. Get this saw disassembled, clean everything squeaky clean, and let us help you get it right. These 660 are cheap and easy to rebuild.

 

[pepe_silvia]

I wouldn't do a vac test right now. In my opinion this saw needs to be completely disassembled and gone over with a fine tooth comb. While its apart, may as well do crank bearings. This thing needs rebuilt completely. Only way to get piece if mind out of it now. Sometimes a guy doesn't have time or money to do it right the first time, but the second time it fails a guy can afford time and money then. Get this saw disassembled, clean everything squeaky clean, and let us help you get it right. These 660 are cheap and easy to rebuild.

I will take this advice. Any suggestions for a one-stop shop to get the parts?

Right now I'm at:

• Clutch
• Intake boot
• Crank bearings

Is the piston/cylinder still a TBD based on vac/compression testing, or will I need to go ahead and get one?

 

[Chainsaw Jim]

At work now, but I'll take a look later. I think I've learned my lesson about buying saws from Mexican Flea Markets, now matter how good the price is .

You didn't go wrong buying it unless you overpaid. The lesson here is to completely go through any used saw purchase before starting or running it.
I always bring my tools when I look at a used saw. T-27 torx, 4mm hex, bar tool, Philips head, flashlight, 8mm socket.
The muffler comes off and the spark plug comes out. Wasting a few bucks gas to turn a deal down is way better than getting burned on the saw.

 

[Chainsaw Jim]

Judging by your piston I'd say the cylinder is likely good to go with minimal aluminum transfer to clean up...if any.
Inspect the bearings. Most like to replace them with every rebuild but it isn't necessary if they're still good. The seals definitely need changed.
There's no reason to worry about vac testing before teardown if you're replacing the seals and other important components since whatever could be leaking will likely be dismantled and reassembled anyways.

 

[tickhound93]

I will take this advice. Any suggestions for a one-stop shop to get the parts?

Right now I'm at:

• Clutch
• Intake boot
• Crank bearings

Is the piston/cylinder still a TBD based on vac/compression testing, or will I need to go ahead and get one?

I am running a farmertrc clutch with zero issues on both my 046 and 066. Buy OEM intake manifold. I would hit up definitive Dave's eBay page. He stocks all kinds of 660 parts

 

[pepe_silvia]

I'm curious to know what the numbers are on the carb. WJ69? The boot looks jacked up enough to maybe be a poorly done modification.

Checked it. It's a WJ69A.