Chain changing tension as it rotates

[Woodtroll]

The crank did not get bent and then unbend itself and then bent again. So don't worry about that.

And the crank is not changing position while you're advancing the chain by hand. The clutch drum should be spinning freely while the crank stays stationary. I don't believe the crank is bent, either, but I'm definitely curious to see what you figure out.

 

[STOVE]

The crank did not get bent and then unbend itself and then bent again. So don't worry about that.

So it’s down to, Oregon versa lightweight bar or the tensioner.

The 28” added too many variables, so I’m wondering if I add the OEM 325 sprocket back and it’s gone. That lays it on Oregon bar alone?

 

[Duane(Pa)]

Observe the protrusion of the nose sprocket teeth as you rotate it. This is dragging on like it's winter or something! lol

 

[Outback]

The tensioner isn't doing anything after you tighten the bar nuts. Forget about that.

You have a wierdly stretched chain, Which I believe you said you eliminated as a problem. I did not reread the thread.

Or a bad drum, rim, drum bearing or bar tip sprocket. Check all of them for play,

 

[dangerousatom]

^^^ I’d have to agree if it’s not the chain it’s the gear on the bar tip.

Clamp the bar in a vice with a square along side and leave a gap between the edge of the square and gear up by the nose. Gap it only big enough for like a credit card to fit between the gear tooth at the 3oclock position. Turn the nose gear and check the gap on each tooth. If it changes ( and its a new bar ) it’s either an out of round gear or the gears center hole was punched off center. A few hundreds up there can cause a few 64ths along the bar.

 

[legdelimber]

That 6 inch~ish travel per change, kinda tilts me towards the nose sprocket.
Figure a smidge more than three times (3.1416...) the diameter of a sprocket and that will get you the distance of one turn of the sprocket.
Might help a little with narrowing it down to which one to stare at.

 

[Seachaser]

Sounds like the bar has some tight spots.

 

[nobird]

Hi all, i'm new here and I stumbled across this thread.
I observed this exactly behavior on my 550xpII buyed last year brand new with 18" bar and .325 chain SP33G.
It got better after cutting of some logs. Now last month i got another new saw 572XP with 24" light bar and with 3/8 C85 chain
and here the chain's behavior is even worse. I haven't used the saw yet, maybe next month, i'll see how it goes.
Maybe needs the sprocket and chain some run-in time ?

 

[Lawless]

Change one thing at a time to find the problem.

 

[jimmorrison]

Hi all, i'm new here and I stumbled across this thread.
I observed this exactly behavior on my 550xpII buyed last year brand new with 18" bar and .325 chain SP33G.
It got better after cutting of some logs. Now last month i got another new saw 572XP with 24" light bar and with 3/8 C85 chain
and here the chain's behavior is even worse. I haven't used the saw yet, maybe next month, i'll see how it goes.
Maybe needs the sprocket and chain some run-in time ?

WTH is going on? Never seen this. New equipment should not be defective. I would return it

 

[Bjorn]

I wouldent worry so mutch. Just run it for a day, then check if it still slacking. Usually the problem Will disapere.

 

[legdelimber]

Are you thinking of flush cutting a couple of dusty stumps to burnish it in?

 

[Bjorn]

Not really. But like many other stuff, a break in period. I have had same problem like this, I just run one tank of fuel. When cutting wood. Problem solve.