Chain changing tension as it rotates

[STOVE]

My money is on a tight bunch of rivets or sloppy holes on the chain. A bearing, rim sprocket or nose sprocket will not give that much wiggle room, unless they are all bad and keep falling on their bad spots at the time as the chain passes......near impossible IMO

One of the reason I keep my used/dull chains in a gallon paint can with like 1' of WD40 in the bottom. Every time i put in a dull chain the can gets a turn over to mix it around. When I decide to sharpen they all get hung on a peg and drip back into the can while im working on one.

In that case as the rest of the chain stretches the whole thing will be
More uniform?

 

[dangerousatom]

LoL maybe
I’m not laughing at ur comment but how we are all spit-balling this.

Have you swapped out the chain yet? That’s were I’d start 1st to figure if it’s the one wonky chain or another more concerning mechanical issue.

 

[STOVE]

LoL maybe
I’m not laughing at ur comment but how we are all spit-balling this.

Have you swapped out the chain yet? That’s were I’d start 1st to figure if it’s the one wonky chain or another more concerning mechanical issue.

I measured the rim tonight at each of the seven points where it steps in. All checked the same.

 

[qurotro]

I measured the rim tonight at each of the seven points where it steps in. All checked the same.

Maybe where the drive teethes sit in is crooked. You cant measure from the outside. One tooth sit higher than the others would cause this.

 

[HumBurner]

Is this a new sprocket or used?

Is the bar tip new or used? If used, have you checked all its teeth? And if replacable-tip used, is it flush with the rails where it meets?

And are you 100% all the drivers are in their grooves while rotating?


Edit: I've had this happen, but only when the tensioner-pin is worn/failing. Sometimes the inserts for the pin wear a little, too.

 

[STOVE]

Is this a new sprocket or used?

Is the bar tip new or used? If used, have you checked all its teeth? And if replacable-tip used, is it flush with the rails where it meets?

And are you 100% all the drivers are in their grooves while rotating?


Edit: I've had this happen, but only when the tensioner-pin is worn/failing. Sometimes the inserts for the pin wear a little,

Bar, chain, sprocket and rim are new.

 

[HumBurner]

Bar, chain, sprocket and rim are new.

I would check the tensioner and associated parts just to have one more thing ruled out.

I find it hard to believe the links would be stretching so unevenly that you'd notice a difference such as what you're experiencing.

 

[STOVE]

I would check the tensioner and associated parts just to have one more thing ruled out.

I find it hard to believe the links would be stretching so unevenly that you'd notice a difference such as what you're experiencing.

I will look into that tomorrow. I cut a few logs down to firewood size this afternoon. Will go retension and check those components

 

[Outback]

My last one was a Chinese rim. It was very loose fitting on the clutch drum, not obviously out of round persay, but it moved alot. Replaced with an oregon one that fit tightly and it was fixed.

 

[Yukon Stihl]

Bent crankshaft…

 

[EFSM]

Bent crankshaft…

Could be, if this problem is only during operation. My impression was that the chain gets loose and tight while spinning it by hand.

 

[Duane(Pa)]

I guess you could hold up on tightish chain and slowly pull the start rope and see if chain gets loose? Wobble wobble

 

[Seachaser]

Replace chain as has even mentioned. This will eliminate that variable.

 

[dangerousatom]

.

Replace chain as has even mentioned. This will eliminate that variable.

Ya I asked that few days ago….?!?

 

[STOVE]

Went back to messing around this morning, took the whole drum and rim assembly off, put it back on.

I think it was some casting imperfections on the inside of the rim where the drivers sit. After running it a little more and cutting it has gone away

Very strange. I’ll be keeping my eye on it. Mounted up my 28” that showed up with the Mike Gott semi skip. No issues. The drum is a Mini 7 spline so I couldn’t try the Oregon rim

 

[Kdrweld]

Possibly check the drive links I’ve seen where they kick off the bar and become mushroomed in sections and they bind as they’re coming around on the bar

 

[STOVE]

Well, the plot has thickened. Got bored between periods of USA hockey. Mounted up a used chain on the Oregon bar again. The situation returned. Move the chain 6 inches and it grabs the bar.

Now I’m leaning towards the bar being involved

 

[STOVE]

 

[STOVE]

I’m thinking I will mount up the original 325 OEM sprocket, bar and chain.

If it does it there I will know it’s internal. Tensioner, hopefully not bent crank as mentioned above. Not sure how the crank would become bent. It was a very low hour saw. Didn’t appear to have ever been disassembled even to clean behind the clutch cover

 

[Outback]

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