Brand new MS391 meltdown

[Old2stroke]

First thing is you NEVER engage the brake unless the engine is at low idle and the chain is stopped. If you start with the brake on, you have to get it off RIGHT AWAY when the engine starts and not re-engage it until the chain stops. Worst case I have seen, this error resulted in a melted side cover, destroyed brake system, destroyed oil pump, destroyed clutch springs, damaged engine case and damaged crankshaft seal. If the engine is running fast enough to engage the clutch and the brake is on, all the power of the engine is showing up as heat in the clutch, it will get red hot.

 

[PV Hiker]

This is why I asked. I have zero problem taking blame and paying for my mistake but in this case I was not at fault and feel there was a malfunction with a brand new saw. I will fight this one all I can. Im hoping Stihl does the right thing. I will keep you posted.

Did I not read you left it in "High Idle" for the duration?

It will only step down to a normal idle when you blip the throttle.

Keeping it in high idle brings the rpm up past the centrifugal force of the clutch springs engagement, so the crankshaft will drive the clutch to try to make the chain go around.

If so this is operator error.

 

[PV Hiker]

It was not on High Idle. That’s why I don’t understand why this occured. I fully understand it’s on me if if it were.

Ok, on post 11 you said above.

If the saw was idling lower than the rpm threshold of clutch engagement.
Then there should be no activity moving the chain. This is normal for properly adjusted chainsaws.

Only way to burn up the clutch is chain brake on and clutch engaged with higher rpms OR you have a bad seized trust bearing.

 

[Mad Professor]

Ok, on post 11 you said above.

If the saw was idling lower than the rpm threshold of clutch engagement. F
Then there should be no activity moving the chain. This is normal for properly adjusted chainsaws.

Only way to burn up the clutch is chain brake on and clutch engaged with higher rpms or bad seized trust bearing.

I bought a filthy used 026 ($95) ran good but on cleanup noticed the clutch cover had started to melt. I tore it down to the case on both sides for cleanup.

There was so much crud under the clutch cover, the friction on the crud looked like the crud started to burn. No damage other than cosmetic on the cover. Not sure what was cut with the saw or how so much offal got under the cover. I'm thinking it was used for clearing brush/trash and lots of stringy crap got wrapped around the chain/drive sprocket and forced under the cover.

 

[Chainsaw Pete]

After the horse escapes from the barn.... From my pov, I NEVER leave a machine running unattended. It is just poor practice. I'm talking about any machine, not just chainsaws.

 

[Stumpzero]

I think there is much more to this story than what is being told.

Tell me what you think I was there and know exactly what I did.

 

[Stumpzero]

After the horse escapes from the barn.... From my pov, I NEVER leave a machine running unattended. It is just poor practice. I'm talking about any machine, not just chainsaws.

I was standing right next to it. It was not unattended. I turned it off because the conversation with my customer.

 

[trains]

Tell me what you think I was there and know exactly what I did.

what you say you did, and the result of what you said happened to the saw just dont add up.

you tell us, im not interested in guessing.

 

[Stumpzero]

what you say you did, and the result of what you said happened to the saw just dont add up.

you tell us, im not interested in guessing.

I was clear with what I did. Read my post and replys. Once the dealership tears down the saw I will know what the damage is.

 

[Stumpzero]

Did I not read you left it in "High Idle" for the duration?

It will only step down to a normal idle when you blip the throttle.

Keeping it in high idle brings the rpm up past the centrifugal force of the clutch springs engagement, so the crankshaft will drive the clutch to try to make the chain go around.

If so this is operator error.

I did hit the trigger and took it off high idle right after it started. The two minutes it was warming up was on low idle.

 

[woodfarmer]

If that is exactly what the dealer told him to do then it is on them!

 

[Sidecarflip]

User error and he does not want to know what I think.

I believe he already knows. One thing for certain and that is, I would have never initiated the thread in the first place.

 

[Old2stroke]

I did hit the trigger and took it off high idle right after it started. The two minutes it was warming up was on low idle.

Yeah,but did you release the brake to make sure the idle was low enough for the chain to be stopped?

 

[Sidecarflip]

I did hit the trigger and took it off high idle right after it started. The two minutes it was warming up was on low idle.

Kind of obvious to me that 'low idle' was higher than normal, high to the point where the clutch was trying in vain to rotate the loop. Oh well.

 

[Mad Professor]

 

[tomsteve]

I purchased a new MS 391. I used it once for no more than an hour. The second time I used it I started it with the chain brake on and let it warm up for two minutes as told by the Stihl Dealer I purchased it from.

IF you can verify and make it factual that the Stihl dealer told you to do that and that is not what the owners manual says, its on the dealer...maybe.

if I'm reading the right owners manual, it states have chain brake on when starting but doesn't say leave on for 2 minutes.

 

[Sidecarflip]

I don't believe I'd ever post pictures of any self inflicted damage when that damage was caused by rank ignorance. In fact I would have never posted the comment in the first place. No Stihl dealer or any other dealer of any other brand, Husky, Echo or whatever would warrant self inflicted abuse that I know of but I'm sure all of them would be more than willing to sell the owner replacement parts and / or charge them the labor to repair it.

Common sense should tell any owner that if the saw is idling so high that the clutch is attempting to engage when at base idle that the base idle is too high and a simple idle screw adjustment is all that is required, but then there are a lot of people today that lack common sense.

 

[JimR]

I would not have asked if I didn’t want to know. That being said I don’t really need any smart ass answers.

IMHO the chain brake is for one reason. That is to stop the chain when the saw has kickback. I never have used a chain brake for anything else.

 

[tomsteve]

I don't believe I'd ever post pictures of any self inflicted damage when that damage was caused by rank ignorance. In fact I would have never posted the comment in the first place. No Stihl dealer or any other dealer of any other brand, Husky, Echo or whatever would warrant self inflicted abuse that I know of but I'm sure all of them would be more than willing to sell the owner replacement parts and / or charge them the labor to repair it.

Common sense should tell any owner that if the saw is idling so high that the clutch is attempting to engage when at base idle that the base idle is too high and a simple idle screw adjustment is all that is required, but then there are a lot of people today that lack common sense.

huge part of why I said "maybe." reminds me of something norm Abram would say near the beginning of every episode of new Yankee workshop:

"Before we get started I'd like to take a moment to talk about shop safety. Be sure to read, understand and follow all the safety rules that come with your power tools. Knowing how to use your power tools PROPERLY will greatly reduce the risk of personal injury......."

 

[Sidecarflip]

One thing is for certain and that is, when you initiate a thread on any publically viewed forum, any and all a comments are acceptable and if your 'skin' isn't thick enough to weather them, don't start the thread in the first place.