MS650 questions

[tree monkey]

aftermarket sir clipy thingy went zingy

 

[CR888]

Saws have moving internal parts, AM P/C saws are the same but with extra stuff jumping round.

 

[Mark71gtx]

I pulled the entire clutch assembly off, including the oiler worm gear. I pulled the recoil cover and moved the coil as far back as it will go. I was going to remove the flywheel, but my puller is too small, so I ordered another one. There is still a scraping sound. I pulled the muffler. The piston is stained dark grey/black below the rings. The rings (black from factory) are pliable and have very little paint worn from them. The piston has a few tiny "nicks" in it that can be seen from the exhaust port. I told the owner, waiting on instructions.

 

[drf256]

Is that the only difference? This saw likely has a new top end on it. How could I determine if it is a 650 or a 660 top end? Thanks.

I thought a 650 was the new 064 and a 660 an 066? Should be 52 vs 54mm top end.

If it's that noisy- check for a broken clutch and/or broken oil pump worm gear. The needle cage for the clutch drum may also be shot.

I went nuts once with an 026 that developed a "click" after a few rotations after the jug went in. I figured my machining was off and the ring was catching the transfer edge on one side. I checked it, took another .002 off the base, etc,etc....

The damn oil line was frayed and hitting the clutch as it rotated.

 

[mdavlee]

650 is same bottom end as the 660. Makes swapping the stuff over easier with no extra work on the holes.

 

[Mark71gtx]

Piston pics. The oil pattern on this saw is odd. I am used to seeing a "blanket" of oil on a piston or cylinder wall. This one has a vertical line pattern like you would expect to see when one was scored. The piston is stained black below the rings. The rings show little wear and are pliable. The piston has a few fine "nicks" in it. You can catch a plastic Tube from a carb cleaner spray can on them. Thoughts?

 

[Definitive Dave]

might be just the pic but the piston looks porous to me below the rings, usually the machining on the piston holds oil

 

[Mark71gtx]

The piston has this odd black staining pattern on it. You can see the horizontal lines on the piston, but there is all of that black staining sporadically across the face of it.

 

[Definitive Dave]

"maybe" break in oil on piston was left to sit and got gummy/dark and has never burned off?
the scratchy noise is more troubling to me, the cylly will work or it wont but a ghost noise is sometimes a pita to find

 

[Mark71gtx]

I ordered a flywheel removal tool for this saw since my current one is too small. I am going to remove the flywheel and see if it is still noisy. The saw looks barely used.

 

[junkman]

aftermarket pistons are sometimes coated in a black anti scuff coating ,i think that's what you are seeing ,it does wear off showing silver after a while .

 

[czar800]

Is the flywheel contacting the Jug or the case?

 

[jacob j.]

aftermarket pistons are sometimes coated in a black anti scuff coating ,i think that's what you are seeing ,it does wear off showing silver after a while .

That's what that one is. The jug is definitely aftermarket looking at the shape of the exhaust port.

If it's still noisy then I'm thinking blown big end rod bearing.

 

[Mark71gtx]

The flywheel does not appear to be contacting anything, but I will remove it as soon as my tool gets in to be certain.

 

[Mark71gtx]

Well, my new flywheel puller came in today, so I pulled it. I saw where the last guy jammed a screwdriver or something to get it off last time. It is a freaking poly flywheel! Who the hell does that? Anyway, the noise was still prevalent. I pulled the cylinder, which was barely finger tight. The piston is missing a circlip on the clutch side. The bottom piston ring was also installed upside down. That cheap, crappy ring has a good 1/4" gap when squeezed tight! I will split the case and install the new parts when they get here. Thanks for all of the advice!

 

[Mark71gtx]

Holy ring gap Batman!

 

[tree monkey]

aftermarket sir clipy thingy went zingy

do yourself a favor and get a oem top end for that thing

 

[tree monkey]

I have a good used 660 cylinder for $75.oo, new piston $50.oo

 

[Mark71gtx]

Not my saw. Owner has parts "on the way"