MS661C with a cracked upper AV mount

[Ozhoo]

Yet another "Runs Great" saw! That phrase get's used waaay to much.
Here's the listing for those interested. You can see the broken cylinder fins.

 

[Canyon Angler]

Here's the listing for those interested.

"WORKS GREAT!!"

Thing looks like it got run over by a dozer and then jump-started with straight, uncut ether

"Other than that, the saw Runs Great!!"

"Other than that, Mrs. Lincoln, how did you like the play?"

FWIW, I got a brand-new AM 660 with Meteor p+c, Caber rings, Taiwan crank, Oregon clutch and a lot of OEM parts, with around 170psi compression, thing pulls like you wouldn't believe...delivered...for less $ than that train wreck...I can refer you to the ebay seller if you're interested, Mike...

 

[andy]

I tend to look for honesty and the good in people. However, in situations like this I I is hard to do so. I cannot imagine how this saw could have been considered as a running unit.

I get that and appreciate it a lot. I Try to look for the same in people... it's usually there.

You might still be best off returning that saw.
Clutch side case, Cylinder, Piston, Brake Flag cracked, .... You need a lot of parts.... expensive OEM parts.
I bet the tank probably leaks after that impact as well.... Who knows what happened at the flywheel side.
There is not much left to salvage for the $360.
When a Saw experiences "Hulk Smash!" it's best to run.
Someone probably dropped that saw out of a tree, dropped a big chunk of tree on it, and then fell on top of it to finish it off!

 

[Mike Canterbury]

Thanks for the alternative suggestions. I’m keeping the saw and moving forward with the rebuild. It has been torn down to the crankcase and all parts have been cleaned and inspected. I have a parts list that needs to be ordered once I find time to stop in at the dealer. This includes a clutch side crankcase, bearings, seals, gasket kit and a new bar stud. I’m thinking an aftermarket meteor C/P kit with rings should be an affordable option. I’m leaning toward an aftermarket air cleaner kit too if the budget allows.

 

[Mike Canterbury]

Hey guys,

Thought I’d post an update that the saw has been returned to its original functional state. There were no issues replacing the clutch side of the crankcase. Everything lined up perfectly. I used a Hyway 56mm cylinder and piston kit as a substitute for the more expensive OEM version. Side-by-side visual comparison did not yield much of a difference. Although, the Stihl had less imperfections in their casting process. I’m still being cautious as I go through a break in period to ensure everything is ok. So, far no issues. It did challenge me during the initial start up. I put in the cold start position and allowed it to run for 60 seconds to calibrate. However, I failed to follow the instructions fully and kept trying to pull the throttle after the set interval and the saw would die. After completing a carburetor clean out and sticking to the prescribed steps, it ran perfectly. Thanks for all the help throughout this project.

I must admit, I should have bought a running unit to begin with. It really stung when my wife said, “you bought a blown up saw! Why didn’t you just get a new one?” I’ll remember that next time.

Take care and be safe folks.

 

[Canyon Angler]

Glad to hear it turned out OK, thanks for letting us know.

 

[CsClimbr]

Well hopefully it works out for you. Wish you luck. The 661 is a great tool when it is
I'm far, far from an expert but have a recent experience that can be shared as wisdom.

.....Make sure you pull the clutch cover and the plate that covers the chain tensioner and look for cracks.
The earlier 661s had an issue that could come up on the clutch side crankcase..... cracks !

The Cause?..Some say user error... others say Stihl design mis-happery. Whatever the cause make sure you don't have the issue.
It will cause vacuum issues and poor run-ability and eventual failure. (probably soon)

Stihl made changes in later releases indicating... they discovered something they engineered needed a "patch".
I'd say that answers the question of whose feet the fault lies.
Your machine has a failure on that side already.. Whatever caused that av mount to crack may have brought the other "known" issue to the surface as well.

If you have anything that looks like this... send it back for sure.

I’m curious to know if their “re-engineered” patch clutch side case half has a different part number.. It’s definitely something I plan to inquire about when ordering a new half as I plan to tackle this replacement. This pic looks similar if not the same as the saw I just purchased from a fellow AS member..

 

[Wood Doctor]

This case break likely occurred when the saw was yanked on really hard when trapped in a pinched cut. But, that burned out piston also means this saw was not run by anyone who cared for it. I recently bought a 661C that has none of this abuse for about $800. It runs perfectly and I will likely get another one from the same logger in the near future. He respects his equipment because he has a family to feed. OP put lots of good work in this saw to save it from the land fill. He also has my respect and admiration as well. Mike, two thumbs up!

 

[Mike Canterbury]

I’m curious to know if their “re-engineered” patch clutch side case half has a different part number..

That is a good question. I already pitched the old cracked crankcase so I have no way to verify your concern at this point. Just as an FYI, I ordered part number 1144-020-2911 and it came with the bearing and all the necessary pins/studs pre-installed. It also came with a new seal too. While at the dealer, we spoke about the broken AV retainer cavity in the upper section of crankcase. The technician said that he was aware of three other saws with the same brake. One of them was on his bench. He called Stihl and they said it was news to them that they were braking. There is no doubt that the saw I bought was severely damaged at some point during operation and they attempted to run it with a split crank case. There was a helicoil installed in stud hole near the clutch. Good luck with your rebuild too. Feel free to contact me if you have any questions. I would be happy to share information from my lessons learned throughout this project.

 

[Mike Canterbury]

OP put lots of good work in this saw to save it from the land fill. He also has my respect and admiration as well. Mike, two thumbs up!

Thanks for the positive feedback Wood Doctor. I had my doubts along the way, but thankfully it all worked out in the end.

 

[pioneerguy600]

This is good news and good to know that case halves for this saw and hopefully case halves for the newer generations of Stihl saws can be purchased and will fit properly, unlike the older saws that had fitment problems when unmatched case halves were joined. This shows an advancement in machining capabilities that Stihl is just catching up to. Happy to hear you got your saw back together, was plenty of work and parts needed but they are good saws.