MS 461 is breaking my heart

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Cytotoxic

ArboristSite Lurker
Joined
Dec 14, 2018
Messages
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Location
NJ
12/14/18
I have a MS 461 purchased new in 2015 along w an outdoor furnace. I do not use the saw commercially , just to cut enough firewood for the winter. In 3 years the saw has only cut roughly 50 cords of wood.

I run a 20” bar and have primarily used Stihls premixed fuel. I recently started to burn VP Small Engine premixed fuel, 50:1.

With that said, this past weekend I pinched the bar pretty good in a deadfall. I had to use the tractor to free the saw. After freeing the saw , I could not get the saw to idle or run for longer then 10-15 seconds.

I noticed an abnormal amount of resistance of the chain and assumed I bent the bar restructing the chain and possible causing the saw to stall. Turned out the bar andchain were fine but the Sprocket was tweaked. I replaced the Sprocketand the chain moved freely but the saw would still not idle ir stay running.

I checked the air filter and fuel filter both were unremarkable . It will idle and run longer when the saw is cold and shorter once it has warmed up.

I thought maybe the exhaust was restricted so I pulled the muffler and the screens were unremarkable. No carbon build up or apparent restriction.

Yet the saw seems to continue to starve .
Is this new fuel bad news?
Did pinching the bar have something to do with this or just a coincidence?

* I plan to run it w the gas cap cracked tomorrow to check the vent cap. Other then that im stumped.

Any ideas or advice would be greatly appreciated.
 
My saw knowledge is limited. Most if the things I have checked already has come from this site . So I thank you. I will add that to my actions tomorrow.
 
Generally when you are tuned right with the regular E10 gas, and then switch to canned fuel, you will run RICHER i think because the 10% alcohol in regular fuel has less energy than straight gasoline. Everytime i've used the canned fuel the tune needed to be leaned out a little. Especially noticeable is that it idles slower with a more sluggish throttle response.
 
I forgot to mention that even though it turns over and runs for a moment, I went ahead and changed the plug.
The prob still existed ecen w the intake boot off.
 
Copy that. I thought the boot was the rubber I removed to get to the plug.

I will have that and the impulse line checked tomorrow as well. I appreciate the help fellas.
 
I think the 461 is one of the best saws EVER made. You got 50 cords and 3 years out of it, why not fix it right. Take it to the dealer this one time and get it all tuned up and adjusted for your mix. I would suggest 40:1 because the only oil your piston, rings and bearings get is the oil in the mix. 50:1 gets it to pass emissions, 40:1 help lubricate. Mike
 
Considering I thought the intake boot was the air baffle , I’m going to do just that. Unfort most of the local guys are at a 3 week turn around and Im only half way there in regards to wood. “Winters Coming!”
Was hoping it was something I could knock out quick at home.
 
I was concerned about that as well. Would I notice any existing resistance in the chain movement if that were the case?

With the new Sprocket and New Bar/ chain , it feels pretty smooth.
 
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