Brand new MS391 meltdown

[Stumpzero]

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. After two minutes of Idle (chain Brake on) I turned it off and went to start it 5 minutes later. The saw would not crank as the Plastic around the chain brake was melted. The saw was never reved up while warming up. I took it to the Dealer where I purchased it and they acted like I was trying to run it with the brake on which was not the case. I felt it should have been replaced with a new one. Your thoughts please??????

 

[Vintage Engine Repairs]

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. After two minutes of Idle (chain Brake on) I turned it off and went to start it 5 minutes later. The saw would not crank as the Plastic around the chain brake was melted. The saw was never reved up while warming up. I took it to the Dealer where I purchased it and they acted like I was trying to run it with the brake on which was not the case. I felt it should have been replaced with a new one. Your thoughts please??????

If you have it on high idle as per the starting procedure, with the chain brake on and you don’t take the high idle off right away you’ll burn the clutch up just like you have. Unfortunately it’s user error in this case. The chain brake can be on only if the high idle is off.

Here is a video of the procedure to follow.



It’s likely salvageable, put up your location and someone may be near by who can help you diagnose the exact issues and repair it.

 

[pioneerguy600]

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

 

[NSEric]

You cooked her bud, it's on you.
My saws never sit and idle with the chain brake on when warming up. They idle properly and the chain doesnt spin when they idle so what's the point of having the brake on?
The only time I use the chain brake is when im limbing and climbing through brush, where I might slip and hit the gas when I dont mean to.

 

[Sidecarflip]

Easily fixable on your own dime.....

 

[Marley5]

That's a shame
I agree with above posts, you gotta pull the throttle to remove " high " idle.
Let it warm on low idle with the chain brake disengaged next time.
My chain brake is just an ornament.
Hope you get her fixed.

 

[Mad Professor]

You cooked her bud, it's on you.
My saws never sit and idle with the chain brake on when warming up. They idle properly and the chain doesnt spin when they idle so what's the point of having the brake on?
The only time I use the chain brake is when im limbing and climbing through brush, where I might slip and hit the gas when I dont mean to.

I'll use the chain brake if I have to drop start it too.

 

[ZeroJunk]

Easily fixable on your own dime.....

Depends on how bad it is melted.

 

[DND 9000]

Yes as all the previous posters had said, it is user error. Always blip the throttle immediately when the saw has started with attached chain brake to remove the high idle. Otherwise it happens what you`ve done.

 

[PV Hiker]

Yes as all the previous posters had said, it is user error. Always blip the throttle immediately when the saw has started with attached chain brake to remove the high idle. Otherwise it happens what you`ve done.

Yes to all that replied above.

WHY did your dealer say to warm it for 2 minutes? You live in Florida. 30 seconds is enough - With the chain brake OFF of course. Just feel with a bare fingers around the cylinder head on clutch side for warmth.

When working the saw hard I'll let it idle - with chain brake OFF - for 30 to 45 seconds to bring in more cool fuel and air across the cylinder to cool it down. Sometimes put it down and move a log it may idle longer.

As mentioned, have a repair person strip down the clutch side and see what parts are needed for repair. The very worst case is the case half is beyond repair and needs to be replaced.

You can show us pictures here and members can point you in the best possible solution.

You are doing good asking your questions here and learning to avoid problems in the future.

 

[Mad Professor]

If you are lucky it's just the clutch cover melted not the case.

That's one of the reasons I hate plastic clamshells.

 

[ballisticdoughnut]

Yeah unfortunately you’re not gonna get a new saw and will likely have to pay out of pocket for repairs which isn’t gonna be cheap. The engine housing will need to be replaced along with any other chain brake and/or clutch parts that are damaged. Engine housing alone is $142 dollars and will require the saw to be completely stripped down. Any hope of warranty will have to be approved by either your regional distributor (not the dealer you bought it from) or Stihl USA and is not likely to happen.

 

[Old2stroke]

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

Oh, I think someone should tell him.

 

[Stumpzero]

If you have it on high idle as per the starting procedure, with the chain brake on and you don’t take the high idle off right away you’ll burn the clutch up just like you have. Unfortunately it’s user error in this case. The chain brake can be on only if the high idle is off.

Here is a video of the procedure to follow.



It’s likely salvageable, put up your location and someone may be near by who can help you diagnose the exact issues and repair it.

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.

 

[Stumpzero]

If you have it on high idle as per the starting procedure, with the chain brake on and you don’t take the high idle off right away you’ll burn the clutch up just like you have. Unfortunately it’s user error in this case. The chain brake can be on only if the high idle is off.

Here is a video of the procedure to follow.



It’s likely salvageable, put up your location and someone may be near by who can help you diagnose the exact issues and repair it.

I don’t have alot of Chain Saw experience so I had watched this video before I used the saw along with many other videos.

 

[Stumpzero]

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

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

 

[Stumpzero]

You cooked her bud, it's on you.
My saws never sit and idle with the chain brake on when warming up. They idle properly and the chain doesnt spin when they idle so what's the point of having the brake on?
The only time I use the chain brake is when im limbing and climbing through brush, where I might slip and hit the gas when I dont mean to.

Dully noted on not using the Chain Brake. Thanks!

 

[Stumpzero]

Yes to all that replied above.

WHY did your dealer say to warm it for 2 minutes? You live in Florida. 30 seconds is enough - With the chain brake OFF of course. Just feel with a bare fingers around the cylinder head on clutch side for warmth.

When working the saw hard I'll let it idle - with chain brake OFF - for 30 to 45 seconds to bring in more cool fuel and air across the cylinder to cool it down. Sometimes put it down and move a log it may idle longer.

As mentioned, have a repair person strip down the clutch side and see what parts are needed for repair. The very worst case is the case half is beyond repair and needs to be replaced.

You can show us pictures here and members can point you in the best possible solution.

You are doing good asking your questions here and learning to avoid problems in the future.

When I purchased the saw the salesman advised me to let it idle 2 minutes before cutting with it. Sorry I didn’t take pictures , wish I had.

 

[lone wolf]

When I purchased the saw the salesman advised me to let it idle 2 minutes before cutting with it. Sorry I didn’t take pictures , wish I had.

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.

 

[Stumpzero]

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.

The saw is in the dealer’s hands so I can’t take pictures.