Chain loosening

[sean donato]

I've used all sorts of chains and not had constant stretch issues even with some dirt cheap ones. After a little run time they will settle in. That sprocket is junk. Replace it. Inspect your chains pretty closely for goofed up drivers. Checking the oil pump is a good idea too. I've replaced the oil pump twice now on my 192tc. Stupid thing hardly oils enough so as it is. Doesn't take much for them to loose a but of capacity and chains and bars suffer. Fines in the tank, worn pump drive gear etc.

 

[barfer]

I mean… chains *do* stretch… even brand new ones… but not instantly.

And that sprocket may well be junk I personally just can’t tell from those particular pictures. But sprockets aren’t expensive. You can buy them on Amazon for ~8 bucks each if it’s a standard 17mm mount sprocket… so you might as well replace it. But like I said no sprocket is going to destroy a chain instantly unless it’s like… missing teeth or something

So… I’d soak your chain in oil before you mount it. Make sure your oiler is working. And see what you find. And personally I like to keep a spare chain on hand so you might as well get a new chain if you can afford one right now because if your last chain in question has been stretched almost immediately after mounting then that chain is going to be worn unevenly and have weird stretchy spots in it and you’re gonna have to do something about that chain anyway if that’s true. If not you’ve got yourself a spare chain.

But soak it in oil overnight before you throw it on there.

 

[Bludenz]

I mean… chains *do* stretch… even brand new ones… but not instantly.

And that sprocket may well be junk I personally just can’t tell from those particular pictures. But sprockets aren’t expensive. You can buy them on Amazon for ~8 bucks each if it’s a standard 17mm mount sprocket… so you might as well replace it. But like I said no sprocket is going to destroy a chain instantly unless it’s like… missing teeth or something

So… I’d soak your chain in oil before you mount it. Make sure your oiler is working. And see what you find. And personally I like to keep a spare chain on hand so you might as well get a new chain if you can afford one right now because if your last chain in question has been stretched almost immediately after mounting then that chain is going to be worn unevenly and have weird stretchy spots in it and you’re gonna have to do something about that chain anyway if that’s true. If not you’ve got yourself a spare chain.

But soak it in oil overnight before you throw it on there.

Thanks for your reply again. I can't be bothered waiting for shipping, I'll just pop into my stihl dealer and pay the premium. I'll try the sprocket first, see how the chain fits with new sprocket. I'll need to check the bar sprocket as well. If the chain is fine I'll try running it etc...

How do you recommend I check the oilier? Measuring the output? It definitely oils, and in my opinion it oils enough, but we'll see.

 

[barfer]

Thanks for your reply again. I can't be bothered waiting for shipping, I'll just pop into my stihl dealer and pay the premium. I'll try the sprocket first, see how the chain fits with new sprocket. I'll need to check the bar sprocket as well. If the chain is fine I'll try running it etc...

How do you recommend I check the oilier? Measuring the output? It definitely oils, and in my opinion it oils enough, but we'll see.

Stihl’s tech manual (at least the old ones used to recommend holding the bar above a light surface or piece of paper to see if oil was coming off the chain and spraying into the paper” LOL. Low tech, I know. But that’s what the manual said.

But soak that chain in bar oil before you throw it on.

And by the way if your chain is mangled (stretched unevenly) it will destroy your brand new sprocket. So… either lay it out flat and carefully measure it to make sure it isn’t unevenly stretched like someone else explained. Or get another chain. Because if you’re gonna pay forty bucks for a sprocket you really don’t want to ruin it right?

And personally I do Amazon prime and get a lot of stuff shipped overnight free. They even sell like sets of 3 sprockets of 7 or 8 or however many teeth you want and those sets are really inexpensive per sprocket… maybe check it out

 

[wildwes]

How do you recommend I check the oilier? Measuring the output? It definitely oils, and in my opinion it oils enough, but we'll see.

Hold the tip of the bar about an inch from a piece of cardboard. Run it wide open for a few seconds, you should see plenty of oil slinging onto the cardboard.

Oil and gas should run out about the same time as well.

FWIW, the only consistent stretch issues I normally see, even with cheap chain, have been from lack of oil.

 

[Bludenz]

Stihl’s tech manual (at least the old ones used to recommend holding the bar above a light surface or piece of paper to see if oil was coming off the chain and spraying into the paper” LOL. Low tech, I know. But that’s what the manual said.

But soak that chain in bar oil before you throw it on.

And by the way if your chain is mangled (stretched unevenly) it will destroy your brand new sprocket. So… either lay it out flat and carefully measure it to make sure it isn’t unevenly stretched like someone else explained. Or get another chain. Because if you’re gonna pay forty bucks for a sprocket you really don’t want to ruin it right?

And personally I do Amazon prime and get a lot of stuff shipped overnight free. They even sell like sets of 3 sprockets of 7 or 8 or however many teeth you want and those sets are really inexpensive per sprocket… maybe check it out

Ha, I actually use that test all the time. I have the saw running and will hold the tip and the butt of a large log. Revving it up it will shoot oil onto the log. I've done this test for this saw and it's shot quite a bit of oil.

What does soaking the chain in oil achieve? Does it clean the chain or do something to the metals? I'll get a new chain either way but this chain is almost a new one...

 

[barfer]

Hold the tip of the bar about an inch from a piece of cardboard. Run it wide open for a few seconds, you should see plenty of oil slinging onto the cardboard.

Oil and gas should run out about the same time as well.

FWIW, the only consistent stretch issues I normally see, even with cheap chain, have been from lack of oil.

Yeah that’s what I meant to say

 

[Bludenz]

Yeah that’s what I meant to say

My one passed this test - meaning the oilier has the correct amount of output right?

 

[barfer]

Ha, I actually use that test all the time. I have the saw running and will hold the tip and the butt of a large log. Revving it up it will shoot oil onto the log. I've done this test for this saw and it's shot quite a bit of oil.

What does soaking the chain in oil achieve? Does it clean the chain or do something to the metals? I'll get a new chain either way but this chain is almost a new one...

Yeah I use that test all the time too… (shrug)

As for soaking the chain it LUBES it. Can’t have too much lube on a chain. And before its run the first time just like you hear anecdotally that ‘90% of engine damage happens at start up’ on cars it’s because the oil is all in the sump and the motor is running dry for like a millisecond or whatever… doesn’t apply to our two stroke saws but it applies to a brand new chain.

Lube that baby up. If you happen to have a can of spray silicon lube spray it on the chain after its mounted (lots of oils have silicon additives and it’s not going to hurt your bar oil)

 

[barfer]

My one passed this test - meaning the oilier has the correct amount of output right?

Yep. That would mean your oiler is working. But remember your chain started out dry right? So do what you want but I always lube up my chains before I throw them on… (shrug)

 

[Old2stroke]

Are you adjusting the chain tension with the bar tip help up? If you are adjusting with the bar down (tightest point), and using heavy pressure when top bucking, the bar will migrate to it's most "up" position and the chain will become very loose.

 

[Bludenz]

Are you adjusting the chain tension with the bar tip help up? If you are adjusting with the bar down (tightest point), and using heavy pressure when top bucking, the bar will migrate to it's most "up" position and the chain will become very loose.

Ahh. This is an interesting point. I've been reading about keeping the bar tip up. How I've been mounting my bar on this ms192t:

1) Flip chainsaw on it's side -> clutch cover side up.
2) Remove clutch cover
3) Put on bar
4) Loosen tensioner
5) Put on chain
6) Tension roughly
7) put on clutch cover and bar nut.
8) Flip right way up
9) Tension chain, snug down bar nut, check tension.

So no, I haven't been holding the tip of the bar up. Does this make a significant change? I'll remove my sprocket, bar and chain and tension it with the bar tip up. I'll see if this changes anything before purchasing parts.

 

[barfer]

Ahh. This is an interesting point. I've been reading about keeping the bar tip up. How I've been mounting my bar on this ms192t:

1) Flip chainsaw on it's side -> clutch cover side up.
2) Remove clutch cover
3) Put on bar
4) Loosen tensioner
5) Put on chain
6) Tension roughly
7) put on clutch cover and bar nut.
8) Flip right way up
9) Tension chain, snug down bar nut, check tension.

So no, I haven't been holding the tip of the bar up. Does this make a significant change? I'll remove my sprocket, bar and chain and tension it with the bar tip up. I'll see if this changes anything before purchasing parts.

Yes. If does. If also aligns the oiler more efficiently. Good call old2stroke

 

[Bludenz]

I'll try mounting my bar and chain this way tomorrow. I'll update this thread if I have any success. Would be going to the Stihl dealer Saturday anyway, so can't hurt to do one more check.

 

[Old2stroke]

I'll try mounting my bar and chain this way tomorrow. I'll update this thread if I have any success. Would be going to the Stihl dealer Saturday anyway, so can't hurt to do one more check.

Keep in mind, if you have a chain that is really sharp, you don't have to apply much pressure to make it cut, especially if it is a chisel chain, in which case adjusting with the tip down isn't too bad. Depending on the fit of the bar on the bar studs, the range of motion between tip up and tip down can produce 1/2" of chain sag off the bottom of the bar. Worst saws are the little ones with one bar stud and the saws with tool-less adjusting, even with the bar clamped as tight as you can get it, you can easily move the tip up and down.

 

[Bludenz]

 

[Bludenz]

Pictures of my bar sprocket. Seems to be in good condition, rotates without much resistance. Bar has some slight burs on it, will dress prior to putting on.

For now, the chain is soaked in oil - will leave this overnight and all of tomorrow until I get home and fit bar and chain.

 

[barfer]

Nice going. I run a pick through the slot in my bars when the chain it off. Basically find a bit of scrap aluminum rod or whatever soft metal you have and run it down the slot on the top and bottom of your bar. You’d be surprised what can find its way in there…

 

[Bludenz]

Nice going. I run a pick through the slot in my bars when the chain it off. Basically find a bit of scrap aluminum rod or whatever soft metal you have and run it down the slot on the top and bottom of your bar. You’d be surprised what can find its way in there…

Will do tomorrow. Thanks for the advice.

 

[barfer]

Oregon I think it is makes a tool specifically for lubing the front sprocket. Basically it’s a syringe filled with heavy grease that inserts through the hole in the bar behind the front sprocket.

After I’ve degreased my chains and bar and cleaned it all up I always lube lube lube them including the front sprocket with heavy grease (not WD-40, not motor oil not something that’s gonna run out of there quickly). So while you’re waiting for parts and have it all apart you might shove as much heavy grease into that front sprocket as you can.