Manufacturing defect or did it run lean?

[MCW]

I know there is a lot of talk here about tuning etc but lets for one moment remember the decline in internal quality on some of Stihl's pro saw lineup since they moved away from Mahle internals. This "may" have caused the damage that Timberwolf showed to start with.
I've attached a few photos below of the internals/porting from my last two MS660's that I bought brand new. Far from perfect and far from Mahle. In fact far from even after market Chinese/Taiwanese kits that I've seen.

MS660 # 1:

MS660 # 2:

See..this is what I like about the TH...a great exchange of information with nobody flaming or taking offence or getting snitty despite differing opinions, and very interesting and informative opinions they are I might add!!!
Ahh, the company of adults...

Unless you start a thread on a Chinese 365 copy Fiona

 

[Al Smith]

Well if those photographs represent the current quality level of Stihl products they are destined to follow the fate of the US auto makers of the 70's .

The later became complacent in good quality because they sold every thing they made .It took imported autos such as Honda and Toyota to show them where the bear chit in the woods thus forcing them to make a better product . If the almighty Stihl doesn't get their head out of butt they too shall follow down that road .

 

[CurSedVoyce]

Sad really

 

[SkwerI]

Are you certain it isn't a knockoff? Stihl dealers are human, too. They are subject to the same moral shortcomings as the rest of us. Is it possible the dealer is selling knockoffs instead of genuine Stihl saws?

 

[Timberwolf]

I've seen a number of them too in the last year and a half, cylinders have a frosted look to them, I suspect the are very high silicon causing grain percipitation. Castings are poor with sloppy work on port edges and some odd port timing. They don't have any country marker like the W, AA or Triangle to say they are made in Brazil, Germany, ect.

 

[Al Smith]

I haven't seen any that looked that rough but then again the occasion has never arose for me to work on a fairly modern Stihl so I wouldn't really know .

 

[Magnus]

I know there is a lot of talk here about tuning etc but lets for one moment remember the decline in internal quality on some of Stihl's pro saw lineup since they moved away from Mahle internals. This "may" have caused the damage that Timberwolf showed to start with.
I've attached a few photos below of the internals/porting from my last two MS660's that I bought brand new. Far from perfect and far from Mahle. In fact far from even after market Chinese/Taiwanese kits that I've seen.

Unless you start a thread on a Chinese 365 copy Fiona

That looks a lot like corrosion.
Even the rings look as they have been bit by something aggressive. Really ugly surface on them...

 

[MCW]

Are you certain it isn't a knockoff? Stihl dealers are human, too. They are subject to the same moral shortcomings as the rest of us. Is it possible the dealer is selling knockoffs instead of genuine Stihl saws?

Dead certain it's not a knock off and both saws was bought from a very well known US dealer. There are no 066/660 knock offs that I've seen...yet...

I've seen a number of them too in the last year and a half, cylinders have a frosted look to them, I suspect the are very high silicon causing grain percipitation. Castings are poor with sloppy work on port edges and some odd port timing. They don't have any country marker like the W, AA or Triangle to say they are made in Brazil, Germany, ect.

Yeah mate and you'd know which site these saws were posted on and by who. It caused a bit of a stir and I'm sure that Stihl don't bank on people pulling their brand new saws down either Ugly ports and finish don't necessarily mean the saw is unreliable but it does indicate what path Stihl may be following and I don't like it. I could post photos of my Husky and Dolmar Mahle internals too but everybody knows they are A1. Pretty sad when even the BB kits I've imported from China/Taiwan have a better finish than these.

Both my 660's were ported so any unsightly finish was removed anyway but sad nonetheless...

That looks a lot like corrosion.
Even the rings look as they have been bit by something aggressive. Really ugly surface on them...

I agree Magnus. It has certainly had something on the piston surface that didn't agree with it.

 

[Al Smith]

In relooking at that piston it doesn't appear those discoloration marks are the typical things left from either a lean run,excessive carbon scouring or dust ingestion so something is definately awry .Was that thing ran on oxignated fuel per chance??

My reason for asking is the fact they remind me of hot rod pistons from a bygone era using a high percentage of hydragon peroxide in the mixture .Very corroisive .Fact being I haven't seen anything like that in about 40 years .

 

[woodworkingboy]

I had a Stihl 076 freeze up on me after the warrantee had expired...not much after. I was running it lean, making a carb adjustment at the time. The local dealer couldn't assist me, other than the costly repair. I called the service rep for my area, gave him my sob story, and he had me send in the saw for evaluation. He had a very sympathetic ear. After awhile I got a call that they were putting in a new p and c at no charge, having found an '"extra nut' when doing the dis-assembly. I knew he was just helping me out. It was a long time ago, but I have never forgotten the kind help on that one.

If they still have the service rep system in place like in those days, it might help to contact him directly if such a situation arises.

 

[Magnus]

It is very important that dealers and rep see this stuff. If they do they get a chance to correct it or prevent it.
Without the feedback the company are flying blind and it will soon run down a good name and reputation... Not to mention making more saws same way as they think it is OK.

MCW. I have seen this surface on rings before.... But never on a saw that had been run recently. It looks like corrosion on the rings as well as piston.

 

[SkwerI]

Perhaps the saw was run using a fuel more corrosive than gasoline?

 

[Magnus]

There is a lot of acids and aggressive stuff in the gas today. Not just benzene... I know what you think, but Alcohol is not aggressive on metals, just braincells..
If it is old pump gas and it gets mixed with new, it gets even more aggressive than just new, but....
To cause this it must to be something extreme!

 

[mastermind7864]

Great stuff guys!!! I like the respectful conversation that is going on here.

On two different Pioneers I've torn down lately that had not been running in years, soft carbon buildup had caused the engine to become "stuck" at TDC. As Al said about the older stuff, the pistons and cylinders were perfectly spotless. Very few of the old saws that ran on 16:1 that I've seen had issues because of the mix.

I don't have near the experience some of you guys have but to me the casting and port finish appear to have been the issue here.

 

[SkwerI]

Great stuff guys!!! I like the respectful conversation that is going on here.

Glad you like it here, Randy.

 

[Al Smith]

To reiterate ,until Magnus made comment about the condition of the piston I had overlooked the fact the rings looked like they were soaked in salt water .This leaves me to believe there is more to the story than just a poorly made cylinder .

I've literally beat the pistons out of stuck engines and none showed that type of corrosion .Except as I said blown hot rod engines ran on rocket fuel that they forgot to run a flush through them or they blew up going down the strip .I'm not saying neccessarily it was hydragon peroxide but it had to have been some oxegonator .Fact I seriously doubt anyone still uses that hillbilly mix any more .I can only remember part of the formula and in the interest of saving someone a lot of grief won't repeat it .

 

[Magnus]

I have seen all kinds of stuff, dameges and materials that should not run, but still run.
I have seen close to perfect work done to saws that won't run faster than I throw them.

There is much involved in trying to figure out what happened.

I explain what and how I do it when i get the more complex cases that most throw under the bench or send out again. I can't do that, I am to stupid to just drop it and say "hey, i'ts not worth it"...

I find out problem, look for the obvious and search systematically thru all system and components until I get a good idea what happened to cause this problem.
Airleak is often discussed and pointed out as culprit as well as damages to membranes/gaskets caused by fuel. You would be amazed if you knew how bad it can be if it is just one leak in one place and you catch it early.

Some things are hard to test on bench so at times swapping parts to a fully functional, perfect saw is needed to see the affects of one isolated issue.
It is never just one issue that cause the result I see as I open the engine. Mostly it is a combination or series of things that lead to a big enough problem that cause it to visit me.

Sometimes it is very easy, sometimes you need to test your patience beyond all reason to get to the bottom of it.
I have a couple saws that I still have to figure out, one that I have more than 40 hrs in to on the bench alone, not to mention testing and research...
It is interest, curiosity, insanity and a fair amount if stubbornness/obsession that keep the fire going. Not alway's in healthy proportions.

I wish often there was a guide or tutorial to turn to when the going gets tuff, but these only cover basic's and not much of the tricky stuff.
Many times I have said that won't work, or that can't be right, still... I stand corrected...

It is not simple to try to figure these things out over internet as there is so many details that I can't get, usually the details that eventually lead to a clue or idea that evolves in to a somewhat qualified guess to start working at.

When you get in to the really scary stuff that is very hard to explain... Operator contact is most often the key.
The more you get to know the operator, the easier the search is.

Thankfully 90 out of 100 saws is just to change a couple parts and of they go......
But the other ten is when the horns start to grow in my forehead.
I need to know........

Countless hrs of talks, research, testing, experiments, more research, disappointing tips and walking thru knee deep BS with slippers...

It is never easy, never exact, never obselute, never repeated in some cases...
But the satisfaction can't be beat!

 

[Magnus]

KISS = Keep It Simple Stupid!

Most often it is first thoughts that are right, even if it is far fetched and seem crazy. If you look it over good enough the parts will tell the tale!

 

[Magnus]

In the mid 80's the fuels here changed fast and the variations were multiple.
It was hopeless to try and see patterns and correct problems. Much like fuels in pumps today as a matter of fact..

We solved it here by developing a brand of fuel specifically for saws. A constant fuel (or as constant as it can be made) and it has done wonders for the loggers here.
It is more expensive, but it has benefits that cover these cost and more.
For us that work with saws we see this in the saws, their engines and tanks and compare it to those with pump gas.

It is not the fuel itself that is so special, it is regular gas with out the additives that are aggressive.
It is the fact that it is constant, already mixed, will not age or separate if stored correct.
This is what makes the money. It is the continuity that makes my job easier and the operators.

 

[Al Smith]

Oh trust me ,I've done my fair share of cussing out saws getting mad and walking away from them .Some of my pouts can last a couple of years but none have beat me yet,I always win in the end .

 

[woodworkingboy]

I've had my share of battles with saws too, but it's one thing when an expensive pro user model challenges the patience, and other when some inexpensive pos makes your hair fall out. A cheap Echo has gotten the best of me, I have to admit. Fortunately the person who owned it suddenly inherited a lot of money, so he said not to bother anymore.

 

[Al Smith]

Oh Lawdy I've had some that I was more familar with their insides than an old girl friend .

I finally inherited the 038 Mag that I've nearly made love to the last 10 years keeping it running .That pot licker will be my next hotty . It will either run like a scalded ape or blow apart like a dollar watch .Come or bleed .

 

[Timberwolf]

Cleaned up a bunch of other manufacturing defects.

Grafted on a little extra stainless on to the muffler deflector.

Cuts dropped from 2.0 seconds to about 1.4, should gain a little once rings seat back in.

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[Al Smith]

Nice work as usual .Now that's what those port edges should look like ,not the surface of a corn cob ,