Stihl MS 291 burnt out after 1 hr

[Brianlol]

Because that would cost them money!!!!! The more saw that they can make that need to be replaced is good for them . That's the only reason for the composite bodies- low cost for them and expendable.

 

[LegDeLimber]

I'll leave it to you guys to continue debating how it happened.

But take a look at the clutch drum/shell, the darkest heat discoloration has two distinct regions.
looks to me like the shoes spinning against the outer portion, heated it and the heat/discoloration traveled inwards to the middle.
Now look at the clutch shoes and center hub/spider.
The entire assembly is severely cooked and the heat had traveled from it, through the crankshaft
then across the clutch bearing and into the center area of the clutch drum.
Take note of how the center region and spur/sprocket have also been discolored.
Seeing as the hub is on the inside of the drum, that would explain the drum being a bit darker in there vs the exterior surface, in that region, about mid way
out from center.

 

[tree monkey]

 

[Brianlol]

Just wondering how ur making out with ur rebuild?

 

[west041]

Too busy at the moment to take it on. My father went out and bought another saw and he already has a 271 so we don't need this one anytime soon.

 

[c5rulz]

Too busy at the moment to take it on. My father went out and bought another saw and he already has a 271 so we don't need this one anytime soon.

Wow, doubling down on fail, 291 to a 271.

 

[Tyrel]

Wow, doubling down on fail, 291 to a 271.

I have a 271. It's a great saw. Really good for milling. Pulls a 32 inch bar no problem.

 

[c5rulz]

I have a 271. It's a great saw. Really good for milling. Pulls a 32 inch bar no problem.

My bad. I forgot about the MS271 applications for milling, especially when pulling a 32" bar.

 

[west041]

Hey guys,
I finally got around to looking at this saw. I've uploaded some pictures. Let me know what you think. So far I know these part were melted and need replacing:
-sprocket/needle bearing 9512 933 2260
-worm gear 1133 640 7100
-oil pump 1141 640 3203
-brake band 1141 160 5400
- I'm guessing that the heat ruined the springs in the clutch and I need a new clutch - 1121 160 2051

I might also need to replace both oil seals but I'm not sure. The heat blueing/discoloration on the crankshaft basically looks like it ends 3/8" out from the seal but that doesn't mean the seal isn't ruined. The other question is do I need a new sprocket? There is just some melted burnt residue on the inside of the sprocket drum that I can probably clean up, but I'm worried that it may have warped due to heat. Here are some pictures:



I'm hoping I dodged a bullet on the engine case. If it needs a new engine case I'm parting it out and putting the money towards a used 260.

If I can fix it and get it going, the warranty is already f'd so I'd like to pull the limiter caps on the carb and drill some holes in the muffler...hope I can get some of your help with that too.

Hope I can have a better time the second time around on A.S. Please don't use the resurrection of this thread as an excuse to do some more bashing on me and my plastic homeowner grade saw. I'm just trying to turn this thing back into a runner.

 

[a. palmer jr.]

In my opinion that case looks pretty bad. A possibility would be to get a used or aftermarket case for it. I don't see them costing that much on ebay.

 

[VinceGU05]

bang those parts in and see what happens/doesnt work properly still due to melted plastic. i an sure that will run again.

 

[pioneer saws]

bang those parts in and see what happens/doesnt work properly still due to melted plastic. i an sure that will run again.

Yep, ive been running a 039 like that for 8yrs now, i got the saw from my work after it was run with the chainbrake engaged, it was written off by the local stihl shop due to the cost of a new plastic case. Its been a good saw, just looks a bit ugly where it melted.

 

[wde_1978]

Yikes. My first post on this thread, I was dubious that could happen, in that the saw would still turn the chain over. I was wrong. My 394 and 3120 won't move the chain at all when the brake is on.

Same goes for my Sachs-Dolmar 105 & 108, and my Dolmar PS-6400 & PS-7900!
Chain brake engages, chain stops moving almost instantly, engine bogs down terribly impossible not to notice!

It seems as if Stihl didn't do proper testing and ended up manufacturing saws that will:
- allow the chain to move even when the chain brake is engaged (insufficient chain brake pressure)
- allow too much clutch slip (weak clutch, too lightly designed clutch weights, too much gap between clutch drum and clutch weights)
- allow the plastic case to melt when exposed to excessive heat (it's an internal combustion engine driven tool featuring a friction clutch, it must be able to withstand a fair amount of heat and then some)

I generally have nothing against Stihl nor any other saw brands, it is just disappointing to read things like this considering that a generic Chinese supermarket saw will do as well or better at a fraction of the price tag, while one still gets a 3 Year warranty.

FYI:
I stopped reading through this thread after the third page (couldn't read any further).
I don't mean to stir the pot nor step on anybody's toes.

 

[a. palmer jr.]

It appears that the saw was melted around where the chain brake mounts, if so you'd probably have to run it without the brake. I guess that's okay since many saws were made without one, I have several of them here. I've never actually had occasion to use a chain brake because even at a time when my saw kicked back the brake didn't stop the chain anyway.

 

[c5rulz]

It appears that the saw was melted around where the chain brake mounts, if so you'd probably have to run it without the brake. I guess that's okay since many saws were made without one, I have several of them here. I've never actually had occasion to use a chain brake because even at a time when my saw kicked back the brake didn't stop the chain anyway.

Well ya get all kinds of advice on the internet.

"Chain brake, we don't need no stinkin chain brake".

 

[a. palmer jr.]

I wasn't exactly saying I preferred no chain brake, it just looks like the brake band won't go in there because of all the melting. Some people run chain brakes and some don't. My saws that I use have them and they are in working order. I just haven't had occasion to use one, that's all..

 

[west041]

I wasn't exactly saying I preferred no chain brake, it just looks like the brake band won't go in there because of all the melting. Some people run chain brakes and some don't. My saws that I use have them and they are in working order. I just haven't had occasion to use one, that's all..

I just unscrewed and pulled the brake band out prior to taking the picture, came out fairly easy. I'm quite confident a new one will fit right in and function fine.

I've never felt a terrible need to have a chain brake on any of my saws so I don't care that much. I do find it handy to be able to lock down the brake when moving through thick underbrush/limbing up, so if I fell I wouldn't accidently hit the trigger and have an accident.

 

[Weesa20]

I have lots of 291 parts from a seized saw . Let me what you need and I'll price it out.

 

[Franny K]

Maybe the saw makers should put a warning light on the top of the saw to let you know that the brake is on while running.

The battery electric Husqvana saw has a little red light that flashes. It also interrupts the circuit.

 

[west041]

Is everyone in agreement that the clutch springs probably got cooked and the clutch needs replacement? I've never cooked a clutch before so I don't know.