Saw stopped cutting once bar buried

[Oldpath05]

I never heard of .043 chain, thats small I run .050 and .058.

 

[Sawyer Rob]

Maybe he meant .063 they make that too.

SR

 

[ernemats]

A lot of the battery powered saws use .043 chain.

 

[Sawyer Rob]

A lot of the battery powered saws use .043 chain.

I didn't know that...

SR

 

[tricky74]

MS171 come with .043 standard. All chains are safety style for them.
I guess a pic would help to show how sloppy the chain is.
On a good chain when you put a straight edge from cutter tip to the bar you get a gap as the chain cuts a wider kerf than the chain.
But if it gets really sloppy the teeth can push back in and there is ZERO gap.
The resulting kerf is too narrow.
I was just suprised how it went from cutting fine to not cutting almost instantly.
Lucky if I actually go anywhere I need reliability I take 3 chains with me.

 

[RandyT]

3/8 LP chains comes in .043 used on electric, pole saws and smaller gas saws and .050

.325 comes in .043 which is new for this year for Stihl and Husqvarna saws, (may be a special mount since both brands are using the same bar and chain part number) .050 .058(Husqvarna) and .063(Stihl)

full size 3/8 in .050 .058(Husqvarna) .063(Stihl)

.404 for large mostly over 90 cc saws in .063 for handheld and .080 for harvesters.

I personally hate the .043 chains since they just don't hold up to hard wood. Nothing like trying a brand new chain in hard white oak and breaking off half the cutters on the first cut. Just too light weight for anything over hobby saws.

 

[yomax4]

In addition to an improperly sharpened chain that s219 mentioned, the saw can cut on a curve if the bar rails are worn unevenly. When it gets bad enough, the bar will bind in the cut. You'll usually notice binding from a curved cut as soon as the back side of the bar enters the cut.

Another problem (sometimes seen in addition to the uneven rails) is getting a burr on your rails.

You can remove the burrs and square up the rails with a flat file, but it's easier to do and you get better results with a bar rail dresser.

I would take a good look at your bar. If the poor lube messed up a chain that badly, it's likely it messed up your bar as well.

So the rail dresser can dress the top of the rails, Is there ever an issue with the internal groove wearing out? side to side wear? It seems like that's the problem I have had with low cost bars.

 

[John_Mc]

I never heard of .043 chain, thats small I run .050 and .058.

A lot of the battery powered saws and smaller gas saws run it. It's generally a narrow kerf chain - an effort to minimize the amount of power demanded of these smaller saws to drive the chain. Narrow kerf has some disadvantages in bigger wood and when felling (IMO), but it works fine for limbing.

 

[John_Mc]

So the rail dresser can dress the top of the rails, Is there ever an issue with the internal groove wearing out? side to side wear? It seems like that's the problem I have had with low cost bars.

The rail dresser can address squaring up the top as well as removing burrs from the sides.

You are correct that the groove can eventually get too wide. This can happen either because the groove wears out, or if they get "sprung". Premature wear could be due to lubrication problems, cutting in dirty conditions, improper sharpening, or just a cheap bar made from low-quality steel or improperly heat treated. you can also cause a good quality bar to wear more quickly if it overheats due to inadequate lubrication or the bar getting pinched when a tree "sits back" on it, or while bucking a log that pinches closed.

In answer to the question, "how do I know if my groove is too worn out?" there are two things to look for:

1. your driver links should not be dragging in the bottom of the groove
2. The chain will always rock from side to side slightly even with a new bar and chain. To gauge whether this rocking is too much: rotate the chain on the bar until the side plate of a link on the top of the bar aligns above the side plate of a link in the bottom. Lay a straight edge across the sides of these two links. If your straight edge can touch the side of the bar when you press on it, rather than being held off of it by the two links, the bar is too worn or sprung.

I have seen advertisements for a bar rail closer which is intended to squeeze the rails back together to make the appropriate gap. I have never used one, but would assume there is a limit to what they can correct for, and that it probably works better on a sprung rail than on a worn one.

 

[dfkrug]

You are correct that the groove can eventually get too wide.

Good post, JOHN.

A sloppy chain groove can be caused several ways, as you point out. Lack of lube is #1 groove-killer, IMO.

I have used clean, but used tractor hydraulic oil as chain lube for many years, without problems. The OP mentions some "tackifier" additive. I do not know what that is, but maybe it is not helping to lubricate?

Anyway, cheaper consumer-grade saws, like the MS171 have wimpy oil pumps that may contribute to groove wear. AND, keeping the oil hole in the bar open is critical when it comes to oil supply. A chain lube test should be run every tank as a minimum, plus watch for paint loss next to the grooves as an indicator of over-heating.