Sthil MS340 Chain tensioner

[Mark_Skyland]

As previously mentioned the chain tensioner doesnt do anything once the bar nuts are tightened up. It's either that the bar isnt being clamped properly for some reason, its an oiling issue or a poor quality chain/bar IME.

 

I would check its oiling correctly and go from there.

 

 

 

 

[ESS]

Its surprising how much the tensioner does assist with keeping the chain tight. I have seen saws where the tensioner has been missing the fibre blocks and retainers , particularly on older saws , the screw has been able to float or work itself loose , and the bar is a bugger to keep tight.

We have had saws break an adjuster out on site and used a lever in the bar groove to tighten to get through the day,the chain can be tight as , but will not stay tight as long as with the screw in.

[Yorkie064]

On 04/09/2020 at 18:50, Stubby said:

If it has a floating rim it would run ok . If its a spur maybe not . Just a little tip . When replying to someone you are having a chat with its a good idea to click the quote tab when you reply ( as I have been doing ) that way the person gets a notification .  I dont know when you are replying to me unless I go on that thread and scroll down .

Stubby Many thanks for the info and gen on quote tab

[Yorkie064]

On 04/09/2020 at 19:58, Ratman said:

Has it got the metal plate that sits over the studs against the crankcase fitted? It sits between the bar and crankcase, looks like the pic below.


 

Ratman...its does not . Thanks Dave

[Yorkie064]

On 04/09/2020 at 23:11, Mark_Skyland said:

As previously mentioned the chain tensioner doesnt do anything once the bar nuts are tightened up. It's either that the bar isnt being clamped properly for some reason, its an oiling issue or a poor quality chain/bar IME.

 

I would check its oiling correctly and go from there.

 

 

 

 

Thanks Mark...its a Sthil bar and only recently replaced so I will double check the clamping and oil system. Thanks

[Mark_Skyland]

15 hours ago, Yorkie064 said:

Thanks Mark...its a Sthil bar and only recently replaced so I will double check the clamping and oil system. Thanks

NP but dont just listen to me ESS has had different experiences which I dont doubt.

My experience has been with only a couple of saws ive used that have had the tensioner missing, once tighten up the bar didnt move.

 

I am fairly sure this issue has cropped up on the forum before on a different model of machine. It could be worth a search.

 

 

 

 

 

[ESS]

I would have the thought the reason bar tips are held upwards when tensioning is because otherwise they could move once cutting.

Imagine a saw without a tensioner cutting both on fore and backhand and its easy to see how a chain would work slack.

[Yorkie064]

All

Many thanks for all your comments. I tried a new bar which negated the issue for about 15 mins but then had the same problem. I bit the bullet at that stage and put it in for repair. Turns out the oil feeder pipe was hard restricting flow- I look at the oil flow after each refuelling stop and there was oil but clearly not enough!  Hopefully sorted in next couple of days. Dave