MS251 Wood Boss

[TnShooter]

Hey all.

I have recently been helping my neighbor cut firewood.
He has a MS251 Wood Boss. The saw runs like a champ until you put it in wood.
Once in the cut it bogs bad. The chain still turns but it lacks sufficient power and chain speed
Any thoughts on what to look for?

Air filter is CLEAN.
Spark plug is NEW
Fuel is fresh 93 Octane - Ethanol Free - with Stihl Synthetic @ 50:1 (1 gallon bottle mix)


After all, the neighbor did buy a new saw for me to use while helping him.
He didn’t like me using my saws on his stuff.

I’d really like to get his 251 running as the current saw I’m using now is running a 24” bar.
Which gets a tad heavy and cumbersome after awhile.

 

[Andyshine77]

How new is the saw? Make sure the air filter is clean, make sure the spark arrestor isn't blocked. I hope the saw was tuned properly by the dealer, if it's lean it won't cut well and engine damage is possible.

Sometimes guys that are used to forcing a saw through the cut do to a dull chain, have issues with saws that have a sharp chain. With a good chain the saw should self feed through the wood, with little force used. Not saying that's what is happening, but I've see it before.

If you find nothing you could have engine damage, at that point with you're lack of experience taking it to a good dealer may be you best option, especially if still under warranty.

 

[TnShooter]

It’s a 2015 model. The saw ran fine when new.
The chain and bar are NEW.
The Oiler is new.

I have experience with some small engines.
Mostly Blowers and String Trimmers.
I’ve rebuilt the fuel system on a Husky 455.

I just haven’t seen an issue where the saw runs excellent at idle and WOT.
But as soon as it starts a cut, it looses all power.
I don’t think it’s the clutch. As the chain still turn.
I haven’t done a compression check. I figure this would be a good start.
Like I say, it isn’t my saw, hopefully once we get this wood up. I can help him take a look at it.
I figured I would ask first, maybe get a good place to start looking.

Thanks for taking the time to answer and trying to help.

 

[Todd Loosli]

I have the same saw and had the same problem. On my 251 I couldn't get the carb adjustment correct for my altitude 6800 feet so I got a new carburetor from flebay cuz I wanted a extra. I removed the adjustment stops on the extra carb and then I could get it adjusted for my conditions. Runs great now. I don't like the stops on a saw and my guess is that stihl didn't get the stops made right with enough adjustment to get it tuned for all conditions. My opinion only but it fixed my problem

 

[Andyshine77]

A compression test wouldn't hurt. A slipping clutch would overheat and create smoke pretty quickly, inspected it for signs of overheating.

And again if it's tuned lean it will fall on it's face in the cut.

 

[mountainlake]

I'd go with the tuned lean and gutless. Steve

 

[Manic84]

Maybe this will help, you can use it as a checklist/reference. Hope it helps or points you towards a solution.

Merry Christmas!

 

[HarleyT]

Put up some pics of the chain!!

 

[TnShooter]

I will see if I can get some pics.
But it is a NEW bar and chain.

Apparently the Oiler had stopped working at some point.
This caused the bar and chain to get hot and wear out.
It was replaced and is working correctly.
It slings oil of the bar.
Again, this is just what I have been told. My neighbor usually cuts a lot of firewood.
I happen to notice his wood pile was low and asked him about it.
So, I offered to help him. He just purchased a Husky 460.
He’s not in the best of health and so I’ve been running it for him.
Since he didn’t like me using my saws.
But cutting the smaller stuff with the 24” bar is not alway fun.

 

[TnShooter]

Maybe this will help, you can use it as a checklist/reference. Hope it helps or points you towards a solution.

Merry Christmas!

Thank you Sir.
This will likely help me.

 

[TnShooter]

I have the same saw and had the same problem. On my 251 I couldn't get the carb adjustment correct for my altitude 6800 feet so I got a new carburetor from flebay cuz I wanted a extra. I removed the adjustment stops on the extra carb and then I could get it adjusted for my conditions. Runs great now. I don't like the stops on a saw and my guess is that stihl didn't get the stops made right with enough adjustment to get it tuned for all conditions. My opinion only but it fixed my problem

I have a the same saw. But so far. Mine works great.
And yes, there seems to be limiter caps or stops.
As my my neighbor stays, he tried to “adjust” it. But the screws don’t turn far.

Again, I haven’t even taken a look at it.
I just like to get it back running for him.
I honestly don’t think he’s goin to like the 24” Husky.
Not until he get a 20 or shorter bar. He’s older and not in the best of health.
I’m just doing my best to help when I get time.

Thanks for the help.

 

[HarleyT]

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