Sky, got a saw question for ya.

[Aaron]

Bought brand new saw couple months ago, haven't had a chance to really use it till today. Problem is that after 15 min or so of cutting, the chain hops off. Try to go and put it back on the bar and you actually have to push the links in to get them on track, particularly in the center of the bar. Did this twice with two brand new chains. My thinking is that the bar is faulty and expands too much when it heats up, pushing the chain out. Ever had that happen?

 

[greybeard]

Sounds like the oiler isn't working right and the chain and bar are expanding.

 

[Aaron]

Brain must be on the fritz today as I can't figure why that didn't come to me right off the bat. Thanks GB.

 

[skyhightree1]

Aaron sorry I just saw this.. GB response is a possibility... Take the saw hold throttle open pointing at something fairly close like a piece of cardboard and let it run a while and see if it flicks any oil off onto the cardboard.

What type of saw is it? Some saws the tensioner is crap and that will happen all the time. The tension on the chain is very important. The other aspect is a defective bar potentially or bar not tightened enough. Check the drive links to see if any are misshapen .. Check the sprocket as well. I had that issue once but it was a defect on the chain. Take bar off clean out oiling port and bar clean it out with carb cleaner and make sure bar completely clean of debris then do the test. Check the chain closely and the drive sprocket on the saw.

 

[fenceman]

All true above. I'm going to add that bar damage can occur when the first chain came off.
of course a new chain will always need to be tightened up after its first few minutes.

 

[skyhightree1]

All true above. I'm going to add that bar damage can occur when the first chain came off.
of course a new chain will always need to be tightened up after its first few minutes.

I would add that I don't put new saw together then immediately cut or new blade and chain I let it run for few minutes cut it off recheck chain tension and that everything is functional then cut. not saying how anyone does it is wrong that's just my way.

 

[dun]

I've found that once it jumps off the bar, frequently the drive teeth are burred and unless deburred will just jump off again. If the drive teeth don;t basicly fall/easily slip into the bar they may have a burr on them.