MS650 questions

[Mark71gtx]

My friend dropped off another six saws for me to work on. One of them is a Stihl MS650. I noticed the cylinder is painted black. I saw that Bailey's sells a black one, but did they come black OEM? I kind of doubt it, but figured you all would know. Peeking through the spark plug hole, the P&C look excellent, crosshatches still visible. As I pull the starter rope, I hear a lot of noise - like a scraping. I initially thought the bearings were shot, but there is no wobble present. Are these generally noisy? I am in diagnosis mode on this one (only spent a few minutes on this one last night). I will pull the clutch drum and the flywheel cover off tonight to see if it still makes noise. If the bearings are shot, this will be my first saw that got a crankcase split.

 

[mdavlee]

Never seen an OEM cylinder black for any saw. Should be quiet like any other saw.

 

[junkman]

sounds like an aftermarket top end ,pull the plug ,and the recoil cover then roll the flywheel by hand ,this makes it a little easier to feel the drag if there is some ,,if crank bearing is out the flywheel could be rubbing on the coil

 

[Mark71gtx]

I have never seen a black top end on any saw before, but I have learned to never say never a long time ago... I am fairly certain that this saw toasted a top end, which was replaced, but they fixed the damage - not the cause. I have a feeling I will be splitting this one... Thanks for the input!

 

[junkman]

I have never seen a black top end on any saw before, but I have learned to never say never a long time ago... I am fairly certain that this saw toasted a top end, which was replaced, but they fixed the damage - not the cause. I have a feeling I will be splitting this one... Thanks for the input!

One of my hybrids has a black oem top end ,says mahle on it ,the builder sprays them all black he does for some reason .

 

[Definitive Dave]

Convert to 660 easy -easy
Dave

 

[Mark71gtx]

@Definitive Dave, enlighten me please...

 

[Definitive Dave]

Top end from 660 will bolt rihht on

 

[Mark71gtx]

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.

 

[czar800]

How's the piston look through the exhaust?

 

[czar800]

I would say that what ever caused it to need a new top end was never fixed and it ruined the new one?

 

[Mark71gtx]

I have not pulled the muffler yet. I looked in from the spark plug hole and I could see all of the crosshatch marks on the cylinder. I think it is new, or it has had little to no use.

 

[Mark71gtx]

I am assuming the new top end was installed and then they couldn't get it to start or run properly and got rid of it. It is all speculation really. The gas smells like hell and there is a hole in the fuel line just before the filter.

 

[Gypo Logger]

Here's a 650 I once built.

 

[junkman]

pull the muffler cover off ,roll the piston down and measure the piston ,i think 52 mm will be 650 ,54mm will be 660

 

[Gypo Logger]

More 650 stuff.

 

[jacob j.]

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.

 

[Definitive Dave]

pull the muffler cover off ,roll the piston down and measure the piston ,i think 52 mm will be 650 ,64mm will be 660

Check yer maths partner lol

 

[Definitive Dave]

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.

Or a fastener stuck to flywheel ;0

 

[junkman]

Check yer maths partner lol

Fixed it sir .ty