Stupid amount of chain stretch?

[Bwildered]

I judge a man by the direction that his toilet swirls....

And it shows, I think we'll call you Arther, Arther understanding of the world.

 

[BangBang77]

I have to assume the 24" sugi. Has
the adjuster hole 'the same' as the Stihl 3003 and not the same as the 20" sugi"?
Maybe it's something they have changed to be more suited to the Stihl instead of an 'inbetweener' design?

If you can confirm that then I can offer you some possibilities regards to as why it worked for a year without issue?

WBF,

Yes, the 24" I went to is a Sugihara. The tail section of the 20" Sugi and the 24" Sugi were identical (prior to my new adjuster holes).

The tail section isn't a critical dimension in the sense of chain tension / fitment unless the bar stud slot is contacting the rear bar stud. The dimension between the adjuster holes and the bar tip is more critical, I would think.

What is your opinion?

 

[Westboastfaller]

WBF,

Yes, the 24" I went to is a Sugihara. The tail section of the 20" Sugi and the 24" Sugi were identical (prior to my new adjuster holes).

The tail section isn't a critical dimension in the sense of chain tension / fitment unless the bar stud slot is contacting the rear bar stud. The dimension between the adjuster holes and the bar tip is more critical, I would think.

What is your opinion?

100% correct.
I probably wasn't very clear.
(Clarify tomorrow, heading to bed.
but yeah!
Very strange, to say the least.

 

[MacAttack]

You said the chain gets tight and loose with every revolution of the sprocket and clutch drum, is that correct? That would rule out a bad crank but it could be an out of round clutch or sprocket, which I think you are already checking. If the engine was turning over and getting looser and tighter the end of the crank could be bent from new. Try rotating the fly wheel and engine crank to different locations then moving the chain by turning the clutch at each of those locations. Would that make any difference in this loose tight scenario

I think we need to see a video of the crank stub at idle with no clutch / sprocket to make sure it runs true, because it sounds like something is very wrong.

 

[Westboastfaller]

@BangBang77
Lol, Stihl up.
So when you take the chain cover off then can you now ajdust the stud up more with the cover in your hands?
I don't know Stihl saws very well. You said they will actually bottom out on the bottom stud if it was overly stretched?
It's not uncommon for ajdusters to gum up and fool you .. or bend if the bar nuts came loose. I am sure it didn't happen to 6 saws though.

 

[Westboastfaller]

BangBang77
I'm saying' put the stud in the old top hole and try again..."N" that's what she said.
Then 'pull it off' and see if you can screw the stud up?
I bet you can't????
-------
If that's the case then I would think maybe their chains are pre stretching a bit more.
I heard someone talking on here about Stihl changing the ingredients in their chains fairly recently???
May be why the Sugi did work for that year period.

Those are the only two things I could possibly think of to get out of this maze.

 

[RED-85-Z51]

I judge a man by the direction that his toilet swirls....

I think yall need a blunt and relaxx

Sent from my LM-G820 using Tapatalk

 

[SteveSr]

I had a similar issue this week that still has me puzzled.

I run a 20" Sugihara on my 461 most of the time. Typically RS chain unless I'm in something nasty. I was at my dad's farm last week cutting wood (red oak). Dropped 3 trees on the ground and bucked the main trunk with my 066 and grabbed my 461 to finish out the bucking. I couldn't get the chain to tension up? I ran the adjuster to the full end of travel and still had excessive slack/sag with a fairly new RM chain. I had plenty of remaining slot left so I know it wasn't butting up against the bar stud like you see with an excessively worn chain. Sprocket looked good but I threw a new one on there and grabbed a BNIB RS chain and attempted to re-tension. No dice - still at the end of adjuster travel with chain slack. Tried a few different chains with the same result.

I then grabbed a 460 to see if I could duplicate the failure mode. Same problem. I then threw a 24" Sugihara on both the 461 and 460 and it tensioned up perfectly. Finished out the day with the 24".

When I got home, I checked everything again. Clutch, drum, drum bearing, sprocket, bar alignment, bar sprocket, various chains, etc. Same dang problem. I tried the 20" bar on every saw I have that runs a 3003 mount - 026s, 360s, 261, 460, 461, 066. Same problem on every saw.

Finally overlaid the Sugihara bar over a BNIB Stihl 20" ES bar and found the tensioner holes on the Sugi to be about .250" - .375" closer to the tip of the bar. This isn't uncommon when comparing different manufacturers though. I did the same with a BNIB Cannon 20" Superbar and the adjuster holes were very close between the Stihl ES bar and the Cannon.

At the end of the day, I overlaid the Stihl ES on the Sugi and clamp it down on my bench. Transfered the Stihl holes to the Sugi bar with a transfer punch and drilled new adjuster holes with a .250" carbide bit on my drill press.

Everything works as it should now but I'm not sure why I needed to drill new adjuster holes at all. I've been running this 20" Sugi bar for over a year now with no issues.

It Stihl has me scratching my head...

If you add new tensioner holes be sure to check that the oil hole still lines up at each end of the bar travel...

 

[Mike Kunte]

Wow lots of replies, thanks!

1) Everything is the regular 3/8, 0.050
2) I can try to take a video this weekend, I'll be out cutting every day. I was hoping to actually cut straight though the weekend since it's the last 3 days of my permit. There's 0 cell signal out there so may not get it uploaded till Monday.
3) I already measured the used chains and new ones and there is a huge difference as I mentioned before, used ones drop about 1 inch lower than new ones and that's after just a few tanks of gas. It's very clear that a new chain is way shorter.
4) Oil does spray off the bar per the manual. Lately I check it every other cut this has gotten so frustrating and there's a myriad of block letters drawn on various objects in my area.
5) Crankshaft endplay! This one I have no idea about, I don't know what's normal or how to check it. Any tutorials or advise?
6) Already did the new sprocket chain and bar, all 3/8.
7) Sprocket bearing was new at the start of the season and I haven't checked it. Will do.
8) The oil doesn't have any specs on thickness, though it's pretty thick this time of year at 40-50F ambient. I was thinking super thin oil to wash it out, but you're saying thicker is better when cutting dirty? Either way, it's something new to try.

Appreciate all the help. I'll go look at it now.

Hi!

My eye caught the 3/8" 0.050 in this post of yours. The 661 should run a 0.063" gauge. Maybe that was just a typo?

Mike

 

[magnus333]

I had a fun weekend cutting in the snow, only to remember as the sun went down that I was 1.5h away from civilization and my wipers didn't work. Great way to close out the season! Speaking of, I don't understand why commercial permits even have seasons and turns out they are going to issue a couple contracts for next year that run straight through the year. Now to get the saw actually cutting...
I've been into the dealership half a dozen times this week, hanging out with the gold tech and trying every imaginable thing we can think of. After checking out every part on the saw in detail he tensioned it up and took it out back to cut some pine. The saw worked beautifully with 0 stretch after several minutes. Initially maybe we thought it was poor bar oil so he gave me a full tank of the stihl stuff and I went home to lay into some shaggy bark juniper only to have it immediately sag 1/8" after a single decent rip, then up to 1/2" after three more, where the chain was falling 45 degrees out under the bar.
So it's at least partly something to do with the wood or maybe I have some sort of mental issue and I wiggle the saw like a bowl of wet ramen someone tossed out of an airplane at 30,000 ft.

Anyway I brought in a couple big stumps of juniper for the gold tech to lay into and dropped the saw off again. Hopefully we'll know more next week. He should probably get the new drum then as well.

 

[lone wolf]

I had a fun weekend cutting in the snow, only to remember as the sun went down that I was 1.5h away from civilization and my wipers didn't work. Great way to close out the season! Speaking of, I don't understand why commercial permits even have seasons and turns out they are going to issue a couple contracts for next year that run straight through the year. Now to get the saw actually cutting...
I've been into the dealership half a dozen times this week, hanging out with the gold tech and trying every imaginable thing we can think of. After checking out every part on the saw in detail he tensioned it up and took it out back to cut some pine. The saw worked beautifully with 0 stretch after several minutes. Initially maybe we thought it was poor bar oil so he gave me a full tank of the stihl stuff and I went home to lay into some shaggy bark juniper only to have it immediately sag 1/8" after a single decent rip, then up to 1/2" after three more, where the chain was falling 45 degrees out under the bar.
So it's at least partly something to do with the wood or maybe I have some sort of mental issue and I wiggle the saw like a bowl of wet ramen someone tossed out of an airplane at 30,000 ft.

Anyway I brought in a couple big stumps of juniper for the gold tech to lay into and dropped the saw off again. Hopefully we'll know more next week. He should probably get the new drum then as well.

Have you had the problem on any other saw as of today ? If you picked up a different saw right now and cut would it happen the same? All chains sag you know.

 

[Okie]

How did he get the name GOLD tech?
Is that name from how much he charges for his time maybe?

 

[HarleyT]

How did he get the name GOLD tech?
Is that name from how much he charges for his time maybe?

It is referring to his teeth...

 

[JayPopple]

Using a MS 661 and my chains (STIHL/Oregon) won't stop stretching until I run out of room on the bar. It's EXTREMELY excessive, as in I tighten the chain and make 5-7 cuts on a puny 8 inch tree and the chain is already sagging so low it's flopping off the bar at a 45 degree angle and I can fit a finger or two between the chain and bar. Stuff I've done:

1) Verified the chain is not getting hot. First, it doesn't have time to, I use it for 30 seconds and it's already sagging off the track but I also carefully measured with an infrared thermometer numerous times, keeping the chain between 85-95F (30-35C) while the bar pushed 115-120F (46-48C).
2) I pushed the pin in and jacked up the oil to max. It's running 1:1 with fuel and never goes dry.
3) Replaced the sprocket & chain. Sprocket looked pretty worn after maybe 10 tanks of gas. Brand new sprocket with a new chain did the same exact thing and is already starting to look worn after maybe 3-4 tanks of gas.
4) Replaced the sprocket & chain & bar. Switched from a stihl 28 to oregon 20. Same thing.
5) Sharpened every chain like a boss to the point of idiocy, as many as 6 times per tank of gas. It's not dull.
6) Tried loose, moderate and too-tight levels of tightening. As in 1/8" sag, just barely snug to the bar and snug + another quarter turn. Zero difference between the three levels of tightening. I got so desperate I even tried never tightening which delivered the... "expected" results of a chain flying through the air like it just didn't care.

The saw cuts like a dream, smooth as butter with no force necessary and it murders trees like those Murder Hornets murder bees, but I literally spend more time tightening than I do cutting. Meanwhile my cheap CHINESE-CHOPPA!, a no-name brand 45cc, doesn't have these issues and cuts just fine, giving me some assurance I'm not a complete idiot, but it's... TOO PUNY of a saw!

I read that really dirty wood can cause chain stretch, but I assumed that was from heat buildup and dullness? I'm cutting shaggy bark juniper in a super dry and excessively dusty environment so maybe that's it, but I don't understand the physics of this nor why it wouldn't apply to the China-Choppa. Nor what to do about it. I'm about to start removing links but that doesn't seem like it'll solve the problem, just delay an inevitable break.

Please help me be less PUNY! I don't want my mom to like my brother better than me! I MUST CUT MORE WOOD THAN HIM!!! You are my only hope...

I am guessing the chain you have is a bad chain with no temper in it. If you can try an other chain and see if the same thing happens. I would recommend you use a quality bar / chain oil. They are formulated to stick to the chain as it travels and lubricated the assembly over the complete circuit.

 

[HarleyT]

That was his last post.......

Maybe he wasn't kidding about being tossed out of a plane...

 

[Mike Gudgeon]

Ha ha ha ... or buried the whole box-and-dice in a shallow dessert grave, done some sort of exorcism rite and gone to live with the Amish. As far as I know they don't believe in chainsaws.

OP, please come back and finish the yarn.

 

[Huskybill]

When replacing a shot sprocket, one should also replace the chains. As running the damaged old chains will quickly damage the new sprocket.

I dress the bar rails, when changing the rim and chain.

 

[Mike Kunte]

Hey, Mag333!
Have you confirmed the chain gauge to be 0.050" or 0.063"? Even running a 0.058" in a 0.063" bar will give problems. A 0.050" is completely unacceptable and will result in huge stretching issues, since it could never withstand the power of a 661. You need to be running 0.063".

Mike

 

[Mike Gudgeon]

My guess is voodoo chains.or a crank dropped onto a concrete floor and then accidentally hammered by a wayward piledriver before original assembly. But perhaps, as with all true mysteries, we will never know since neither the saw nor the owner seem anywhere to be found!