Saw stopped cutting once bar buried

[yomax4]

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.

Great Explaination. I run high end Stihl bars with CAM2 Bar oil. Maybe I'm trading out my bars too soon. Thanks !

 

[tricky74]

The added tackifier is like the stuff in chain bar oil that makes it tacky and stick to your fingers.
Chain wear was acceptable with good bar oil.
I noticed considerable increase in wear with the other oil.
Maybe I will find the new chain does the same with the good oil after a while.
The bar groove is a bit sloppy but I am ok with it.
Bar lube hole gets cleaned frequently.
Would not buy another MS171 but I must admit it has taken a beating lately.

 

[John_Mc]

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.

I do one almost every time I start the saw, unless I just shut it down a few minutes ago. It doesn't take much: just aim the end of the bar at a log or stump and run the saw a bit. It should start flinging oil off onto the log or stump - you'll eventually set a line of wet oil. The first check of the day, it may take a bit for the oil to show up, but it's good to wait until you see it. You don't want to put pressure on the chain until you know it's getting oil.