Brand new MS391 meltdown

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I don't do that, I start it up let it warm up say about 5 seconds then cut wide open. Let's see pics of the damage by the clutch. You could pull the muffler and see if the piston has damage too and post any pics of that also. Then we will have a course of direction to proceed.
I’d really like to see some pics as well. Thing must have gotten smoking hot if it’s now hard to pull it over. I’ve seen it before and it’s not pretty.
 
I’d really like to see some pics as well. Thing must have gotten smoking hot if it’s now hard to pull it over. I’ve seen it before and it’s not pretty.
I was distracted by a customer and I turned it off but it was still idling fine . When I went to use it few minutes later was completely locked up.
 
I was distracted by a customer and I turned it off but it was still idling fine . When I went to use it few minutes later was completely locked up.

I take "locked up" as in the clutch drum/chain are froze up, not the crankshaft?

Hopefully just the cover melted , # 9.

1 039 covers.png
 
I would not have asked if I didn’t want to know. That being said I don’t really need any smart ass answers.
Jerry’s a very well respected and long time member on here. If you’re fortunate to get his advice you can rest assured it’s right.
 
I would say it’s the melted cover , the clutch and the chain break. Locked up I refer to pulling the start cord and it doesn’t move at all.
 
I would say it’s the melted cover , the clutch and the chain break. Locked up I refer to pulling the start cord and it doesn’t move at all.

You need to pull the clutch cover and muffler off to access the damages.

The crank and recoil should still spin with the chain brake on. Check piston/cylinder with the muffler off.
 
You need to pull the clutch cover and muffler off to access the damages.

The crank and recoil should still spin with the chain brake on. Check piston/cylinder with the muffler off.
The chainsaw is with the dealer and I don’t have access to it. We shall see what they say and I will update on here.
 
The chain should not turn or the clutch be engaging the drum at idle on any saw, much less a new one.
Sometimes you can take a Dremel tool with grinder wheel on it and clean up any plastic that is melted and grabbing the clutch drum.

But, the saw should idle without the clutch engaging anything until the RPM over powers the clutch springs, whether the drum is seized or not.

This is a weird story.
 
@ Stumpzero
Sorry for the misfortune with the new saw and hopefully you get it resolved.
When I hear " locked up " I think straight gassed.
Buddy of mine who is 67, operated saws for many years got his gas cans mixed up and straight gassed a brand new MS 250.
 
The chain should not turn or the clutch be engaging the drum at idle on any saw, much less a new one.
Sometimes you can take a Dremel tool with grinder wheel on it and clean up any plastic that is melted and grabbing the clutch drum.

But, the saw should idle without the clutch engaging anything until the RPM over powers the clutch springs, whether the drum is seized or not.

This is a weird story.
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.
 
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.
Either a clutch spring broke or was not connected. Really no other explanation other than being revved up past the threshold of the clutch engagement RPM . And, that would be operator error. Even if it was a throttle control lever issue it should be obvious.
 

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