Stihl MS310 stops cutting for "no reason"

[MikoDel]

I have a Stihl MS310 with a 20" bar. The bar is newer than the saw, replaced with an Oregon bar around 2011. I swapped in a new bar precisely because I am having this problem.
My chains are SHARP, they throw spaghetti and huge chunks at the beginning of the cut. Just the other day I was bucking some felled maple. The saw starts cutting perfectly, gets about 4 inches down into the log... and then the wood stops flying and the saw loses it's "bite", and it's as if the chain is dull. If I start a new cut... same thing. Great performance at the beginning, then it behaves as if it's dull. I try rocking tip to hilt, and wiggling to try and re-set into the cut. It's very frustrating!

• The chain is tight and sharp
• the saw is throwing oil
• the bar is periodically maintained, i.e. cleaned, filed along the sides to remove any bur or mushroom caused by use, and also flipped every time the chain is replaced.
• the bar does not appear to be warped or bent when sighted from different angles

I don't know what I'm missing but I am open to suggestions. I have a MS200T that cuts beautifully and never gives me this kind of headache. I have also used other people's saws on occasion and have never encountered this weirdness. Thanks in advance for any help you can provide.

I really don't need the expense of another saw right now!

 

[Jehinten]

Your bar can cause that problem. Judging by your post the only cause that I know of, that you did not mention, is the rail widening. You might check for side to side play in you chain. If it has excessive movement, then you need to tighten the rails, or replace the bar

 

[chiselbit]

Or the corners of the teeth on one side of the chain are dull from hitting a hard object.

 

[fhudo]

I have a Stihl MS310 with a 20" bar. The bar is newer than the saw, replaced with an Oregon bar around 2011. I swapped in a new bar precisely because I am having this problem.
My chains are SHARP, they throw spaghetti and huge chunks at the beginning of the cut. Just the other day I was bucking some felled maple. The saw starts cutting perfectly, gets about 4 inches down into the log... and then the wood stops flying and the saw loses it's "bite", and it's as if the chain is dull. If I start a new cut... same thing. Great performance at the beginning, then it behaves as if it's dull. I try rocking tip to hilt, and wiggling to try and re-set into the cut. It's very frustrating!

• The chain is tight and sharp
• the saw is throwing oil
• the bar is periodically maintained, i.e. cleaned, filed along the sides to remove any bur or mushroom caused by use, and also flipped every time the chain is replaced.
• the bar does not appear to be warped or bent when sighted from different angles

I don't know what I'm missing but I am open to suggestions. I have a MS200T that cuts beautifully and never gives me this kind of headache. I have also used other people's saws on occasion and have never encountered this weirdness. Thanks in advance for any help you can provide.

I really don't need the expense of another saw right now!

I think you may find the rails on the top part of your bar are ‘widened’. Try taking a flat file and removing the burr edge (careful as it can be razor sharp). A tiny ridge can cause what you are describing.

Try to rotate the bar from time to time to make sure wear is even.

Let us know how you get on?


Sent from my iPhone using Tapatalk

 

[Stephen Moore]

When my rails get worn I replace the bar, some guys file em and press em, but I’ve found the tip gets worn out too. A chain rocking or the opposite jamming in the bar is a symptom of a worn bar. Time is money, time to spend some money. Get a new bar.

 

[Stephen Moore]

If you like dressing bars I can give you all kinds for the price of shipping.

 

[flyingsquirrel25]

I have a Stihl MS310 with a 20" bar. The bar is newer than the saw, replaced with an Oregon bar around 2011. I swapped in a new bar precisely because I am having this problem.
My chains are SHARP, they throw spaghetti and huge chunks at the beginning of the cut. Just the other day I was bucking some felled maple. The saw starts cutting perfectly, gets about 4 inches down into the log... and then the wood stops flying and the saw loses it's "bite", and it's as if the chain is dull. If I start a new cut... same thing. Great performance at the beginning, then it behaves as if it's dull. I try rocking tip to hilt, and wiggling to try and re-set into the cut. It's very frustrating!

• The chain is tight and sharp
• the saw is throwing oil
• the bar is periodically maintained, i.e. cleaned, filed along the sides to remove any bur or mushroom caused by use, and also flipped every time the chain is replaced.
• the bar does not appear to be warped or bent when sighted from different angles

I don't know what I'm missing but I am open to suggestions. I have a MS200T that cuts beautifully and never gives me this kind of headache. I have also used other people's saws on occasion and have never encountered this weirdness. Thanks in advance for any help you can provide.

I really don't need the expense of another saw right now!

That sounds like a bur on the bar to me. Or unevenly sharpened chain (one side cutting faster than the other). I have a bar dresser in my shop that can be used to determine squareness as well.

Where about safe you in SE PA? I’m in that vicinity as well and would be more than happy to take a look at it if you are close or we are working near by. We are about a mile from Longwood Gardens. But work all over the region (media tomorrow and looking at work in atglen today)

 

[MikoDel]

These replies are appreciated. I did file. There were 2 burs on each side of the tip, presumably from kick. I also checked chain wiggle. It rocks back and forth. (side to side, whatever makes sense.)

Because that movement might be on the sloppy side, I'm gonna go w/a new bar and new chain. As was said "time is money"

 

[Stephen Moore]

These replies are appreciated. I did file. There were 2 burs on each side of the tip, presumably from kick. I also checked chain wiggle. It rocks back and forth. (side to side, whatever makes sense.)

Because that movement might be on the sloppy side, I'm gonna go w/a new bar and new chain. As was said "time is money"

The drivers on your chain are likely fine, the sharpen maybe not s much? The bar may be done as I said previously, but if you still have cutters and haven’t filed any rakers yet, just go with a bar and save some money.