bar tip getting jammed up with sawdust

[Muddy42]

I have an old Stihl MS460 that I run with a Stihl rollomatic 20 inch 3/8 guide bar 3003-000-5221.  When I bought the saw second hand a few years ago I bought the a new bar, chain and sprocket. To give you an idea of use, I am probably still only half way through the life of this first chain.

 

As per the photo, the bar keeps on getting jammed up with saw dust.  The saw is oiling fine I have cleaned out the oil tank, all the lines, oil pump etc. Pump is turned to max.  I can see oil coming out of the oiler hole when I run the saw without a bar.  I can see oil running down the bar when I run the saw without a chain.  When I run the saw with a chain it flings off oil onto a white piece of paper. And it will keep spraying out oil for 10 minutes or so of revving.  However if I cut logs for more than 20 minutes it jams up.  I can free up the tip with a screw driver and oil, and the mechanism seems to run fine, but it keeps happening again. its driving me mental.

 

The only thing I can think of is if I could have accidently pinched or overheated the bar tip early in its life.  No signs of heat or paint discolouration..

 

Any feedback gratefully received.  Should I just replace the bar? Thanks,

 

[Tree monkey 1682]

How olds the bar? I do know years ago orgeon did a similar thing ,or wearing un evenly,  problems with micro warps in the bar , has this suffered the same fate even though its oiling . On our saws the was no blueing, no loss of paint or pinch marks , they to were 3/8th bar .

Have you any other bars / chains to see if it happens on them , say a longer bar and chain?

Also we had an 16 in efco new outta box, it was on max on oil pump and it cooked the bar . Solution was chasing the oil pump costly , but never cooked a bar again 

[Muddy42]

1 hour ago, Tree monkey 1682 said:

How olds the bar? I do know years ago orgeon did a similar thing ,or wearing un evenly,  problems with micro warps in the bar , has this suffered the same fate even though its oiling . On our saws the was no blueing, no loss of paint or pinch marks , they to were 3/8th bar .

Have you any other bars / chains to see if it happens on them , say a longer bar and chain?

Also we had an 16 in efco new outta box, it was on max on oil pump and it cooked the bar . Solution was chasing the oil pump costly , but never cooked a bar again 

 

Thanks.  Ive just checked my email.  The bar is a year old. Its a bit strange. I have had bars tips jam up occasionally, but I can normally fix it and carry on.  I have a spare oregon bar of the same tooth count.  Now I have confirmed the setup is oiling, I will try that.

[markieg31]

I got a brand new Stihl light weigh bar and had a similar experience where the bar sprocket was jammed with sawdust. Cleaned it all out and happened again. On my 15year of cutting I haven't had this previously the to have it happen 3 times in short succession seems strange. Haven't used the saw since but only thing I could think was it was an Oregon chain in a Stihl bar. 

[Muddy42]

Thanks. This was stihl chain and stihl bar and perfect match in terms of pitch, thickness and count. My other saw lasts 5/6 chains before i replace the bar, normally user-induced damage rather than wear. Its really odd.

[Dan Maynard]

I used to get the bar tip bunging up on my 461 but hasn't happened for ages. I'm not sure if it's worn in, chain tension now better, or if I'm just better at clearing chips out of chain by not stopping the saw while still cutting. I don't think it's anything to do with oil, haven't done anything to the pump or tank.

[Muddy42]

11 hours ago, Dan Maynard said:

I used to get the bar tip bunging up on my 461 but hasn't happened for ages. I'm not sure if it's worn in, chain tension now better, or if I'm just better at clearing chips out of chain by not stopping the saw while still cutting. I don't think it's anything to do with oil, haven't done anything to the pump or tank.

 

Ive just burned through 1/4 tank cutting thin air in bursts.  Oil everywhere but no stuck bar.  I might try using the saw for some smaller cuts where the bar tip doesn't get buried.  Maybe that's the problem. I do like my chains slightly on the loose side.

[markieg31]

19 hours ago, Dan Maynard said:

I used to get the bar tip bunging up on my 461 but hasn't happened for ages. I'm not sure if it's worn in, chain tension now better, or if I'm just better at clearing chips out of chain by not stopping the saw while still cutting. I don't think it's anything to do with oil, haven't done anything to the pump or tank.

My problem was/is on a 461, although shouldn't really make a difference.

[Stubby]

I could be mistaken but don't Stihl bars have a plastic bush in the roller tip rather than other makes that have needle rollers ? I don't know if this is relevant . 

[Muddy42]

1 hour ago, Stubby said:

I could be mistaken but don't Stihl bars have a plastic bush in the roller tip rather than other makes that have needle rollers ? I don't know if this is relevant . 

 

It could be relevant, in that the plastic is easier to melt.  I'm going to give this bar once more go then I'll prise the tip open with a screw driver before binning it.  I'll post a photo here!