chain tensioner keeps breaking.

[Magwa24]

Hello,
First time on here. I own a jonsered
2065 turbo. This is my second yr. Cutting with this saw. But this year I was cutting and the cahin popped off. Chain tensioner screw broke in half. Bought a new one put it on, cut half a day and that one broke to. Any ideas why it could be breaking? It has a Oregon pro light 18 inch bar. New last year.

 

[showrguy]

Hello,
First time on here. I own a jonsered
2065 turbo. This is my second yr. Cutting with this saw. But this year Iwas cutting

okay, then what happened ??

 

[turnkey4099]

Hello,
First time on here. I own a jonsered
2065 turbo. This is my second yr. Cutting with this saw. But this year Iwas cutting

Welcome to the forum. Looks like you hit send before finishing but:

I bent the tension screw on my new MS310 then learned that relying on that flimsy screw to take the slack out of a chain it works better to keep picking the chain up from the top of the bar (sort of wriggling the bar) to help ease the load on the screw. Doesn't take near as much force on the screwdriver to turn the screw that way.

Harry K

 

[spike60]

Not sure what might be causing that, but I'd suggest getting a new pawl to go with the next screw. Also, make sure that the bar plate "forks", (don't know what else to call them lol), are grabbing the slot in the screw to keep it from wandering.

last thought; How's your rim sprocket look?

 

[Magwa24]

Not sure what might be causing that, but I'd suggest getting a new pawl to go with the next screw. Also, make sure that the bar plate "forks", (don't know what else to call them lol), are grabbing the slot in the screw to keep it from wandering.

last thought; How's your rim sprocket look?

Rim sprocket looks fine. Some minor wear. I also bought a new nut when I bought the screw. My bar has some slop around the nut. I don't know its pretty frustrating. Its my main blocking saw and its been down almost two months.

 

[Magwa24]

The second time it broke I was falling a huge ash. Was half way done with the wedge cut and the chain got really loose went to adjust the screw it just spun freely. Both time it broke it was the thread above the nut. I hope that helps

 

[066blaster]

is your chain too long? do you really have to crank on it to get it tight? or is it just breaking under regular use? you are tightening it with the bar nuts loose and then tightening the nuts down after?

 

[Magwa24]

is your chain too long? do you really have to crank on it to get it tight or is it just breaking under regular use? you are tightening it with the bar nuts loose and then tightening the nuts down after?

No the tensioner was only about a 1/4 of the way up from the bottom. Yes I did loosen the nuts before I tighten the chain.

 

[redfin]

Are you holding up on the top of the chain when you are tightening the nuts?

 

[nmurph]

Have you owned this saw since new, and are the replacement parts coming from a Jred dealer?

 

[Magwa24]

Have you owned this saw since new, and are the replacement parts coming from a Jred dealer?

No I haven't been holding the top of the blade when tightening. I usually tighten the chain with the saw on its side. And yes the parts are dealer parts.

 

[Magwa24]

No I haven't owned it since new. I was looking at the parts list and it shows some clear bushing that go between the bar and cover. Tjey don't give a part # or name. Mine doesn't have those on it. Anyone know what these are? Thanks for all your help.

 

[Guido Salvage]

I have been running saws for over 35 years and have never broken a tensioner. In order for that to occur there has to be significant pressure. Are you sure that the pin is in the bar slot before you tighten the clutch?

 

[indiansprings]

Welcome to the forum. Looks like you hit send before finishing but:

I bent the tension screw on my new MS310 then learned that relying on that flimsy screw to take the slack out of a chain it works better to keep picking the chain up from the top of the bar (sort of wriggling the bar) to help ease the load on the screw. Doesn't take near as much force on the screwdriver to turn the screw that way.

Harry K

That is the way the owner's manual would have told you to tighten the chain, lifting up on the bar so that your just tightening the chain, not lifting the bar. The most common reason is not lifting the bar and overtightening the chain. Just like bar nuts, they just need to be snug, I've seen studs stripped and pulled out of the case by overzealous hands.

 

[rwoods]

Result of kickback???? If so, read further. On another brand saw, I carry spare tensioners as I have broken more chain tensioners than I can remember - all after a significant kickback. Usually the kickback bends the screw and the screw is sheared when you turn it. When I changed to a grade 8 screw, the pawls began shearing upon kickback. The causes in my case (other than IMO a whimpy tensioner set-up) were overly aggressive depth guides, heavy handed cutting with the top of the bar in log piles where kickback are often and the force of the kickback is re-directed straight back, and not cleaning the bar sides and clamping surfaces (where the cover and case clamp against it) of all the oil that accumulates. It took me a while to nail down that last contributing cause. After making it a habit to clean the clamping surfaces, I haven't broke one since. Ron

 

[Magwa24]

That is the way the owner's manual would have told you to tighten the chain, lifting up on the bar so that your just tightening the chain, not lifting the bar. The most common reason is not lifting the bar and overtightening the chain. Just like bar nuts, they just need to be snug, I've seen studs stripped and pulled out of the case by overzealous hands.

I looked at the manual and It showed some clear spacers. It doesn't give a part # or a name. Could this be the problem? Anyone know what these are called or where to get them? Mine doesn't have them. Thanks again for all your help

 

[056kid]

Back the tension off before cutting..