Saw stopped cutting once bar buried

[tricky74]

My MS171 has been getting treated pretty bad lately to make up for the time it spent broken.
Ages ago I changed the bar from .043'' to .050'' to allow decent chain.
I always run chisel chain on my saws but the only one available was genuine Stihl.
When I made an order for some stuff I bought 3 full chisel chains from Hutzl dirt cheap.
The first chain has been cutting really well and holds an edge ok.
Not long ago I started using the hydraulic oil from my tractor with added tackifier as bar oil.
Chain wear was rapid so went back to good oil.
All of a sudden this week it no longer cuts once bar is buried but still sharp.
Removed chain and compared to a new one and the amount of slop is crazy.
Fitted new chain and it is all good now. Shame the teeth are not even half worn.
But for the price I will order again as I have a lot of dirty wood and treat it pretty bad lol.

TLDR version.

Crap bar oil wears out chains quickly.

 

[RandyT]

Something else to watch is the bar rails. They have a tendency to wear uneven, and can cause issues with cutting circular and the longer the bar the more pronounced it can become.

 

[Jchonline]

Thanks for sharing. I guess we keep using the good stuff!

 

[ericm979]

Semi chisel will stay sharp longer in dirty wood. I've gone back to saving the full chisel chain for felling and known clean wood.

 

[Sawyer Rob]

Do you lower the rakers when you sharpen the chain???

AND NO I don't care if some don't like it when they are called "rakers"... lol

SR

 

[ericm979]

I use a depth gauge depth gauge to set the depth of my depth gauges.

 

[tricky74]

Yes I have filed them down as I go.
But even though the chain is far from used up in terms of cutters I am happy.
I can buy about 8 compared to one Stihl chain.
Semi chisel is also difficult to find in 3/8LP.
I did buy one with the bar and was impressed so bought 3 more and the ones that turned up were standard chain.
Rang the supplier and they said ''oh we changed supplier but these are as good''. They were crap.
I find full chisel better as I try to keep the chain clean compared to a standard chain I treat like crap.

 

[ericm979]

Bailey's has semi chisel 3/8 LP chain. It's their house brand, which costs significantly less than Stihl chain. I use that house brand stuff on many of my saws.

I've been really impressed with Stihl PS3 chain that came on my MS241. It's full chisel and cuts very well, but it stays sharp a long time for full chisel chain.

 

[s219]

If a chain has been sharpened unevenly side to side, it will cause the cut to curve ever so slightly. Once the bar is buried, it gets stuck and can no longer move through the curved cut, and just stops -- like too long of a truck that can't make it around a curved road. Chain may seem sharp but the saw acts like it's revving against air and just won't bite. My guess is that is what your problem is.

Can't be rakers, as they would act about the same whether or not the bar was in the surface or buried.

 

[John_Mc]

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.