MS461R Chain Tension Issues

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Glockem45

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So, I have researched this to death, but my new MS461R with 25" bar and Stock yellow Stihl chain is ticking me off. So here is the brief backstory. I have about 15 tanks of fuel through my new saw and it flies. All I use it for is Noodling at the moment since I have about 4-6 cords of large Northern Red Oak and Scarlett Oak to cut up. The saw is cleaned, re sharpened, and re tensioned after every use. It continues to get a loose chain after say 5-8 25" Oak Rounds that I am Noodling. It gets bad after about 10-15 of these rounds and only stays tight enough to cut 1 maybe 2 rounds before I have to stop and tighten the chain. What could I be doing while Noodling that would do this? There is a lot of grabbing and bogging in the wood also once the chain gets loose and basically stops cutting.

So let's ask the question a different way. What causes a chain to loosen considering the equipment and type of use outlined above? I have never experienced this tension issue on my MS290, so this is discouraging to say the least. Your thoughts?
 
Yes, I lift the bar nose, set the tension, then tighten the front nut, then the rear nut.

I also removed the chrome plate covering the tensioner screw and inspected the travel movement of the screw, it looks fine. When the chain is tightened, about 1/3-1/2 of the tensioner travel remains.
 
Stihl chain is generally pretty good, in my experience it needs to get pretty warm to stretch, either cutting with a dull chain, forcing the chain to cut faster than it wants to, lack of bar oil or too much friction between bar and chain such as bent bar or crooked chain cutters.

Is the oiler on max output? Is it cutting straight? Are you pushing it in the cut? Is the paint coming off the bar anywhere.

What is your chain tensioning method? Do you rotate the chain to seat it before doing up the nuts?

How do you sharpen and adjust depth gauges?
 
Yes I move the chain during final tensioning, then lock the two nuts. Yes it is a Stihl 84 link Yellow chain. I only have one chain that it came with. The chain is quite grabby, and no the saw needs me to work it into the cut then it rocks, but it seems to get stuck in the wood easily and the saw bogs down and stops in the cut. I use the Stihl 2-1 sharpener that handles the rakers as well.

As for oiling properly, who knows. A tank of gas is used and the bar oil is about 80% empty. But I swear I never see oil on my logs or anywhere else.

I seem to wrestle the saw into and during the cut, yet I get stuck quite often. No the bar is not losing paint and looks in great shape.
 
I had a similar issue with a saw of similar size except I was breaking tensioner after tensioner. Why? Too agressive depth guides, repeated kickbacks and too much oil on bar and plates. Cleaned the bar and saw - breakage problem fixed. Eventually the sharpening caught up with the depth guides.

Ron
 
I do have a new 84 link yellow Stihl chain in the box from baileys. I looked at this one, and it has a nice cliff on the cutter with about a 1/16 cliff angle. Mine after using the Stihl 2-1 sharpener just has a nice sharp cutter with barely any under cliff at all.
 
This saw is much more powerful than your previous saw, and may be contributing to the problem.

Possibilities: 1) Dull Chain 2) Tighten the nuts properly, go back and forth several times and make sure they are snug. One nut will often help draw in the other. What you consider tight for your little saw may not be good enough for this one. 3) Oiling, is the oiler adjusted properly, and are all the holes clear w/o obstruction (the hole in the bar can easily get plugged, clean it with a small piece of wire). 4) rakers are too low.

Those are my best guesses, good luck with it.
 
You should be running closer to 1:1 ratio of fuel to bar oil used. Crank that oiler up. I would bet you are heating up your saw pretty good, especially noodling. You are subjecting your saw to many of the same conditions as milling. Sounds like your chain has some issues, too.
 
Sounds like you are have too much hook.....ya may need bigger file or hold it higher. Inner top plate angle needs to be close to spec for smooth cutting. An aggressive chain in hardwood can really beat up on you and your saw components. A close up pic of cutters will make this easy if not to much trouble.
 
A couple things I noticed last night. No, the HO oiler was at the stock setting, however, the adjuster screw only turns about a quarter turn with a screw driver and stops (is this correct for max oil flow) ? And yes, I keep my bar clean, even the two little oiler holes on the bar.

I learned a little more about sharpening last night. I compared a new 84 link Stihl Yellow chain to the stock Stihl Yellow chain I just finished sharpening, and the cutters look very different. The new chain cutter has a sharp edge, plus a 1/16" sloping shelf angle under that. Mine after sharpening only has a sharp cutter and not the angled shelf underneath. ( Sorry for the incorrect names of the cutters). So, I tried my Stihl 2-1 sharpener and added more pressure during the sharpening stroke, this gave the cutter tooth that deeper sharp sloping shelf angle under the cutter tooth (Make Sense)?
 
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