Ms 660

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  • #26
I have no idea thats just how it arrived
 
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  • #27
Parts came
 

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  • #28
New part needle cage and gasket new stihl piston
 

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  • #29
Cylinder on
 

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  • #30
Muffler on
 

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  • #31
By his was interesting 2 differ sizes for the recoil on my other 660 they are all the same
 

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  • #33
Tommarow is test day
 

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  • #35
You are NOT messing around with getting that thing DONE! Cool to see...good luck on the test.
I just get going and it just flows. Nice tinkering thing to just have me time the stihl pro saws really go together well. This wasn't abused or high time makes things easier
 
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  • #36
Saw runs very had it out in some stuff no issues. Had to riches it up it was turning 13.200 a bit high. Maybe I was all the port smoothing I did
 
Please redo your first sentence. I cannot parse out exactly what is supposed to be there. Does it say the saw runs very bad or does it say the saw runs very hard?
 
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  • #38
Must be the auto correct . The saw runs excellent
 
If it ran high, it could be a lean condition and the very reason of the scored piston. Good move to richen it, but keep an eye at it closely in the near future. An air leak is often getting worse and will kill your saw again. The carb setting can correct it at first if moderate, but it might not be enough after some times. If it reeves up again, stop it immediately and investigate.
 
Ooops. Found another 660. Decomp valve was bent and leaked, missing a couple bits and had a loose clutch drum. Apparently up here clutch drums with rim sprocket are NLA. 36" bars are hard to find up here. Dealers are out of stock.
20211001_094122.jpg Runs good now.
 
I watched a rebuild video.

Looks not too complicated.

I have a 660 on the shelf.

Idk the root cause of why mine is scored, though.
It's had a long life.
Is it ever just wear and age, or is it due to a leak or something needing attention, and how is that determined?
 
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In general, there's no good reason for an adequately lubricated by properly mixed fuel using quality mix oil, to score a cylinder, no matter how many hours it has. If that problem is off the table, more likely you have issues with air infiltration from a leaky boot causing lean running, or heat caused by clogged cylinder fins, or a damaged spark plug dropping metal scrap into the cylinder.

I'm no expert. There are more than a few here that are far more knowledgeable than I.
 
I'm a not a saw mechanic.

I think the dealer told me $500 to repair back to stock.

At that time, $1400+ tax got me a 661, IIRC.

With the current saw shortage, I may not be able to grab one off the shelf in an emergency.






How does one test for leaks?

It's dissassembled, atm.

I'll get some pics.

Wonder if i should send it to a saw builder to have it worked over while being repaired.
 
You'd need a pressure tester. Dunno if that's something you make or buy. but the gist is with the saw assembled, you block off the exhaust port, attach your tester to the intake, and pressurize the system. It should hold pressure over a period of time. Some loss is acceptable, but you'd have to look it up. If you have a running saw, spraying wd40 around likely leak points will reveal the leak(idle calms down).

This is what I've gleaned from reading around, and not first hand experience. The mechanics don't interest me so much, so I don't pay full attention.
 

I just took some thick gasket paper, foil taped both sides to make gaskets to fit between carb and boot, and the muffler. just bolt them back on, and use impulse line to vac/pressure test.

in my area, for me at least, being able to fix a saw has always been a bonus. local saw shops are slow, dumb and expensive.
 
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