Excessive chain juddering

[Gnarlyoak]

Situation: Running an Echo CS-360 topper (saw less than 6mth old) with an Oregon 91VXL chain, 12" bar. When cutting larger diameter wood (4"+) I'm getting a lot of juddering from the saw, saw bucks and vibrates excessively in the hand and the saw then has a tendency to bog down in the cut. Taking great care to ensure cutter angles and rakers all filed down to right shape/depth etc but doesn't seem to have any effect. No issues cutting smaller diameter stuff 3" down say...

Any ideas as to possible causes and or solutions to try to fix... ?

Many thanks.

[htb]

Wasgoing to say rakers too deep, but you've already checked. Try a new or anoyher chain and see if its any better

[Rough Hewn]

How old is the bar?
Any dings, bumps, crap in the bar?

[peatff]

4 hours ago, Rough Hewn said:

crap in the bar?

How often do I need to do this ?

Have you squared up the bar rails, checked it for rough edges or tried turning it ? It could be any combination of things really, does it do it with your spare chain fitted ?

[spudulike]

Rakers too low is the most common causes and gives exactly these symptoms as the chain is fighting to cut out too large chip - bit like a wood plane set too deep!

Worth trying a new chain as it may have a fair bit of wear in it.

[Stubby]

You say you have got the rakers the correct depth .  The only other 2 things I can think of is .... The chain drivers are bottoming out in the groove  rocking the chain from side to side ( very worn out bar ) and/or your drive powermate is ridiculously worn making the chain want to climb off it . That's all I have .......

[dan494]

Can't stand that oregon chain, really snatchy. I'd bin it and get a stihl (ideally) or even a rotatech chain over the oregon!

[Mick Dempsey]

1 hour ago, spudulike said:

Rakers too low is the most common causes and gives exactly these symptoms as the chain is fighting to cut out too large chip - bit like a wood plane set too deep!

Worth trying a new chain as it may have a fair bit of wear in it.

Common things happen commonly.....rakers too low.

[woodwizzard]

If it's only when cutting 4"+ stuff, then perhaps it's a lack of power in the saw, slowing the chain down enough to stop the smooth cutting of a fast chain. 

[Rough Hewn]

Have you tried a new chain?