Nose sprocket jamming.

[chilli]

Ringing up a horse chestnut trunk with a 441 & 25" (new) bar. Four times in quick succession the nose sprocket seized solid & stalled the chain. Was cutting at full depth. Bit of a pain having to stop & free up/ clean out the sprocket. Could it have been that the chain couldn't clear the chips quick enough on a full cut?

Could it be a lack of lubrication? There is no grease hole so it would have to be a lack of chain oil. Any ideas chaps?

[Tree Man Tom]

Is it a stihl guide bar?

 

Have you checked the bar is getting oiled?

[Stephen Blair]

Is your chain too slack??sawdust can gather in the groove of the bar at the underside from about 4 inches back towards the nose, so it fills up first then cloggs the sprocket, usually when slowwing down or if the chain gets pinched in the cut. i would take hte chain off and see if the sprocket is ok first though, if it is then its your chain tension or technique i reckon mate

[Canal Navvy]

I had the same with my 441 25" bar combo on it's first outing ringing up.

 

Hasn't happened since.

[Stephen Blair]

give it an extra rev when you lift it out the cut, that keeps it clear. If you are cutting right to the point where the saw is about to jam then this is the problem, being super sharp and new it will be cutting a wee bit beyond where it usually would before pinching.

[Dean Lofthouse]

You should've give the nose sprocket a good oiling or greasing before fitting, on a new bar it takes a while for the oil to work it's way to the sprocket bearing

[Stephen Blair]

You should've give the nose sprocket a good oiling or greasing before fitting, on a new bar it takes a while for the oil to work it's way to the sprocket bearing

 

never had to do this with a stihl

[Tree Man Tom]

You should've give the nose sprocket a good oiling or greasing before fitting, on a new bar it takes a while for the oil to work it's way to the sprocket bearing

 

Dont the stihls have nylons bearings which is why you dont have to grease them?

[Dean Lofthouse]

never had to do this with a stihl

 

Yeeeeehhaaaaaaa

[Dean Lofthouse]

The nose sprocket requires lubrication.

 

You may get away without seizing the nosebar whilst the oil works it's way through but you will damage the bearings or reduce the life of them.

 

Always give a new guide bar sprocket a squirt of oil or grease through the hole if it has one, before fitting and starting

Edited December 29, 2009 by Dean Lofthouse