John Deere CS56 bar/chain woes

[FBrown]

I have a JD CS56 that runs like a dream, is strong and very reliable, despite my novice knowledge of maintenance and lack of upkeep...

Only thing ive done in the three seasons ive owned it is put a primer bulb on it and keep oil/fuel in it.
Cranks on first pull and runs like a top every time.
But i have had a constant headache with the 20" Oregon bar and unknown chain that came with it.

I have read every thread and every manual I can find and have taken it to two different "professional" small engine repair shops and had chain and bar adjusted and then replaced... the chain still wont stay tight. I have tried everything I know how to with no luck. I love this saw, but it will only cut for five minutes and then the chain loosens and hangs.

Doesn't matter what im cutting. It can be a hardwood log, or softwood limbs. After a few initial cuts, and a few minutes of run time, chain sags and before long it pops off.

Additionally the chain will dull quickly. Needs resharpened after each use of just a few short cuts. (And i haven't committed to mastering the art of sharpening the chain, so I have to get an OLD friend to do it who is experienced)

Now me being a novice, i thought well maybe this is an operator error...maybe im not holding the machine correctly, or using the saw right...so ive watched every instructional video i could find on proper technique for different size and weight saws and intended usage...and im confident it's not me. The only thing I haven't done is change the bar. Now i have spent more on the saw than i paid for it...i don't want to sell it, but i dont want to keep spending money on it if it wont serve me ...

Ive suspected maybe bar is bent, but i can't visually tell that it is. It doesn't seem worn badly. Could the chain adjust spring be weak and need replaced? If so, where do i order just that part? Or could it be a sprocket or bearing issue?
Ive not seen any similar problem mentioned on any forum. Any help will be appreciated.

 

[holeycow]

do you hold the nose of the bar up when you snug the bar nuts?

is the chain adjuster pin located correctly?

are the bar nuts correct?

 

[dougand3]

Doesn't matter what im cutting. It can be a hardwood log, or softwood limbs. After a few initial cuts, and a few minutes of run time, chain sags and before long it pops off.

That sounds like you're tightening the chain on a sprocket ridge, then later, the chain finds the valley and gets loose. Inspect sprocket. Here is a severe example:




The other option is your chain tensioner screw doesn't stay tight or the pin is worn and doesn't hold bar. You are getting pin seated nicely in the bar hole, right?

 

[FBrown]

@holeycow the nuts were on it when i got it and seem to hold tight so im assuming they are original.

@dougand3 I have the bar aligned with the hole ... adjuster pin...? Not sure what that is, but yes, I elevate the nose of the bar when tightening the chain. Everything under the cover fits together well, seems tight and not worn much if at all, except for the sprocket seems to travel a bit back and forth on its shaft...not sure if this is normal or not but it doesn't wobble or seem loose.....Sprocket doesnt seem worn where valleys are at all to my novice eyes.

Attaching some pics: after closer inspection today, it seems bar might have a slight bend in it...perhaps from getting pinched while cutting?

I rotated the chain slowly after checking to make sure everything was assembled properly and tightened. As i rotated the chain it was tight against the bar with a little give as it ought to be, but after a couple of turns of the sprocket, the chain loosened...a couple more turns and it tightened back up. (See pics) so I cranked it up and cut a little into an old elm trunk laying in the back yard. After 30 sec of run time the chain was hanging. See pic.

I am beginning to think the bar is bent...it HAS been pinched by some big branches a time or three in the past...before I learned how to cut properly with it...so tell me what you guys think...buy a new bar or troubleshoot more?

 

[wcorey]

I believe the cs56 were originally supplied with .325 pitch chain, someone could have changed everything over to 3/8... but...
You have a 3/8" chain, check that the chain is the same pitch as the rim/sprocket and bar.

Chain does look pretty dull and maybe appears to have been sharpened with too small diameter of a file, should be 7/32".
Or the tips of the cutters are just beat down so far it looks like that...
And check the rakers/depth gauges, looks like by the time those cutters are brought back to sharp it might be getting time to lower them...

 

[pioneerguy600]

I would suggest pulling the clutch off and inspecting that rim drive sprocket, it looks hammered in the pict. That is usually the suspect in chain woes like this one.

 

[dougand3]

Agree the rim sprocket looks worn. It "floats" on the clutch drum splines = normal side to side movement. Gotta remove clutch and inspect.
The tensioner pin is the nut that moves on tensioner screw. It has a nub that goes in bar tensioner hole.

 

[Little Al]

do you hold the nose of the bar up when you snug the bar nuts?

is the chain adjuster pin located correctly?

are the bar nuts correct?

All of the above + does your bar studs have shoulders on them inboard of the threaded part? if yes an easy to prove if this is the cause of the problem is to bore/drill out from the inside of the clutch cover the bar fixing holes approx 1/8 inch the size of the shoulder this will allow the cover to tighten down on the bar & not be held away by the stud shoulders If you have doubts assemble saw less clutch cover & pack out bar fixings with washers & see if that cures the problem Did the saw come with Chain guide shims? are they still fitted

 

[FBrown]

One more thing i forgot to mention...although the chain seems to get oiled well when in operation, the saw leaks bar and chain oil. I have made a practice of storing the saw on its side because upright it will leak all of the oil out. Not sure if that tidbit of information is relevant to my intermittent loose/tight chain phenomena.

Thank each of you for your insight thus far, but I'm beginning to feel like I need a hands on troubleshooter as it appears some disassembly will be required and I just don't feel confident I know what im looking for.

Can anyone suggest a knowledgeable chainsaw service shop in Arkansas?

 

[FBrown]

I believe the cs56 were originally supplied with .325 pitch chain, someone could have changed everything over to 3/8... but...
You have a 3/8" chain, check that the chain is the same pitch as the rim/sprocket and bar.

Chain does look pretty dull and maybe appears to have been sharpened with too small diameter of a file, should be 7/32".
Or the tips of the cutters are just beat down so far it looks like that...
And check the rakers/depth gauges, looks like by the time those cutters are brought back to sharp it might be getting time to lower them...

I think im gonna order a new clutch/sprocket/bearing combo for $26 on Ebay and a fresh 20" Oregon bar and chain.

After a few youtube instructables, I think i can swap all of that out with no problem. The tensioner screw seems to be moving freely and the bar stud doesn't look damaged, so...i think it's worth a shot.

So, help me make sure i get everything compatible. What pitch chain/bar/sprocket do i need to have to put it back to factory specs?

 

[Huskitoter]

Welcome to AS.

I wouldn't be surprised if dougand3 hit it. The bar has a bend close to the mount. That may be throwing the chain off center and preventing it from seating or making it kick out before you get the chain tightened. Check it with a flashlight.

That sounds like you're tightening the chain on a sprocket ridge, then later, the chain finds the valley and gets loose. Inspect sprocket. Here is a severe example:

View attachment 699850


The other option is your chain tensioner screw doesn't stay tight or the pin is worn and doesn't hold bar. You are getting pin seated nicely in the bar hole, right?

 

[Legion Prime]

I rotated the chain slowly after checking to make sure everything was assembled properly and tightened. As i rotated the chain it was tight against the bar with a little give as it ought to be, but after a couple of turns of the sprocket, the chain loosened...a couple more turns and it tightened back up.

A picture of the bar adjuster and one of the bar where the bar adjuster fits would be helpful as well. Could there perhaps be a bent crankshaft in the equation here?

 

[holeycow]

Sometimes a bar with a “little wow” in it can be straightened satisfactorily by bending it by hand, or blocking it and standing on it, or putting it in a press or vise. You just have to bend it back “over centre” and it might find it’s happy, straight spot again. Or not.

I’ve only done a couple. They held straight after a proper bend-back.

 

[FBrown]

A picture of the bar adjuster and one of the bar where the bar adjuster fits would be helpful as well. Could there perhaps be a bent crankshaft in the equation here?

 

[dougand3]

Chain tensioner looks fine. You need to pull clutch and change rim sprocket. They are consumables. Lots of youtube videos on clutch removal procedure. Or maybe a member here is near you to help.

 

[Huskitoter]

Do you slide the sprocket inward (off the drum*) before putting the chain on it? My chain won't seat right if I don't do that.

Edit... I should have said "away from the drum" instead of "off the drum". The chain may not seat into the sprocket if you don't slide the sprocket to the middle of the splines before installing the chain. The sprocket will center after you run the saw, which allows the chain to seat and become slack.

 

[dougand3]

The rim sprocket won't come off the drum splines inwardly when installed. If it does, you're missing parts. And you would throw the chain in 5 secs if rim could leave splines when installed. Rim will move 1/4"-5/16" on the splines, which is normal.
Until the clutch/drum/sprocket come off the saw - you're rearranging the deck chairs on the Titanic.

Where are you in GA? Maybe a member is close by and can help. Or find a shop that will remove clutch for fair price. You can replace sprocket/drum/washers/clutch w/o tools.

 

[FBrown]

The rim sprocket won't come off the drum splines inwardly when installed. If it does, you're missing parts. And you would throw the chain in 5 secs if rim could leave splines when installed. Rim will move 1/4"-5/16" on the splines, which is normal.
Until the clutch/drum/sprocket come off the saw - you're rearranging the deck chairs on the Titanic.

Where are you in GA? Maybe a member is close by and can help. Or find a shop that will remove clutch for fair price. You can replace sprocket/drum/washers/clutch w/o tools.

Im actually in AR. After a little more YouTube homework... I feel confident I can handle the clutch/sprocket removal and reinstall. Gonna order some new parts and install and touch base with u folks when i get it all back together...

 

[dougand3]

Oh, yeah. I was looking at other post location. Clutch isn't hard - just remember CLOCKWISE-LH threads to remove.

 

[FBrown]

Oh, yeah. I was looking at other post location. Clutch isn't hard - just remember CLOCKWISE-LH threads to remove.

Okay so im hunting online for parts and it seems OEM specs were .325 but an optional 3/8 is offered for sprocket and bar/chain. Which do you guys suggest? What is the advantage of one or the other?

I suspect perhaps my sprocket and chain may have been mismatched by the shop that installed...could this be the culprit for my woes?