Throwing chains

[PES+]

Poley.....you can also put the bar and chain on and see if it runs almost all the way out to take up the slack leave off the side cover and just run the bar nuts down finger snug to check

The only thing that is puzzling if that is the case is the wear pattern on the bottom of the cover plate.....but that plate is bent and may be warped in the rear at the bottom

 

[Poley4]

other pics

I took some more pictures, it is hard to get the one lengthwise of the bar, so I did sight down the length of the bar and it appears to be straight, although it is a little hard to tell with the crown in the bar. I got a pic of the 2 bars standing up on edge side by side and they appear straight that way also. If you put the new bar and old on top of each other, the tails match perfectly. As for the number of drive links, the the 2 oregon and 1 stihl chains are all 78 drivers which is what the Shindaiwa manual specs out. The clutch bearings and the sprocket nose bearings feel smooth and roll freely. I do try to grease the sprocket bearing at each fuel-up. The chain looks a little rough, but I did put it on new before I started today. It didn't help the looks of the chain when 2 of the trees I cut up today were hollow and full of that wet black crap.
Thanks again

 

[sILlogger]

no oiler holes??

looking at pic 10 i noticed that those bars don't have oiler holes on that side of the bar. this meaning that when the bars we flipped no oil would get to the chain=weird, and not good. at least that is how it would be on a stihl. dows shindiawa have a different way of doign things?

 

[Poley4]

oil hole

looking at pic 10 i noticed that those bars don't have oiler holes on that side of the bar. this meaning that when the bars we flipped no oil would get to the chain=weird, and not good. at least that is how it would be on a stihl. dows shindiawa have a different way of doign things?

Yeah, I thought that at first too, but then I got to looking and seen that the upper adjustment hole lines up with the oiler slot on the saw.

 

[PES+]

The wear shows to much taper on the tail or wrong number of links

Count the drive links and make sure all the chains are in fact 78s

Line it up like I said with out the cover and see where it sits with all the slack taken out.

Then do the same with the new bar and chain the same way and see where the tensioner sets

You also need to remove your plates and make sure they are shaped properly I know the cover plate is out of shape on the bottom rear and which happened when the chain derailed and bent the corner back on the bottom front.

Also check and make sure they are the correct plates....they should match the magnesium casting under them when you remove them. I have seen pretty much all brands have wrong bar plates on occasion new out of the box.

Only possibilties
1) wrong number of drive links or excess stretch in chain
2)wrong plates or bent plates (but you should feel drag when you move the chain by hand)
3)wrong bar tail profile (for the called number of links)
4)wrong rim sprocket (not likely from the wear pattern)



It looks like Gypo had the right call on taking out a link

 

[Poley4]

Thans Pest

Thanks Pest, I will double check all of those things tomorrow.

 

[Poley4]

Guys,
A couple more questions. The saw came new with an Oregon chain, is the bar made by Oregon too seeing how it is stamped "Made in Canada" on it? If so, if I replace the bar, should I change brands?

 

[PES+]

Whoops.....

one more..make sure your cutters are the same length and angle and that all the rakers are the same height

When you check it with the chain on it you should be able to take up all the slack in the chain well before the middle of the adjustment range

 

[Poley4]

Whoops.....

one more..make sure your cutters are the same length and angle and that all the rakers are the same height

When you check it with the chain on it you should be able to take up all the slack in the chain well before the middle of the adjustment range

Where the adjuster sits in this pic is where it was set when I took the bar and chain off. I haven't sharpened any of the chains that I have used on this saw yet, they were all new when installed. I like to have a 4 to 6 chains for each of my saws then when they are all dull, I sharpen all of them on a chain grinder and start over. The only thing I have done to the Oregon chain in the previous pics is I ground off all the safety bars.

 

[PES+]

That explains the damage I saw.....throw that chain

You do not have them all ground the same height and that style chain needs the bumpers.

Modifying any chain can cause real damage and can be dangerous sometimes.

If you want non safety pro chain buy it that way

You have caused more wear on the bar by having the bumpers all different heights and sharp edges left to catch and jam in the cut.

It almost certainly contributed to the original thrown chain.

Straighten out your bar plates to original shape and try the new bar and chain
and never try to grind off any links if at all possible as it can get expensive
again if you want non safety pro chain buy it that way

I have seen a few situations like this and it hardly ever turns out well.

 

[Poley4]

The origional chain that came on the saw new was an Oregon 33SL chain. It threw that chain within the first hour of running the saw. There were no modifications made to this chain in any way. The second chain was a Stihl 23RS chain, which doesn't need any modifications, the saw has thrown this one as well. The third chain was also an Oregon 33SL chain which is the one I modified, was only installed today, or I guess now yesterday seeing that is 1:00 a.m. So the modified chain cannot be the culprit.

 

[dtnodya]

My Observation FWIW...

I was looking at the chain in picture 10 ... I photoshopped some arrows ....

Something is causing the chain to get messed up like that and it almost has to be the bar ...... I guess

 

[Jaxx]

Just wondering, how do you keep your saw so clean? You have probably already checked the alignment of your sprocket and the rails. Also, on one bar I have, one of the sprockets appears to be off, at one position, the chain is snug, at another position (moving the chain), the chain is not snug. I don't recall you saying that you tried a different bar? Good luck clearing up the problem.

Jaxx

 

[dtnodya]

Just wondering, how do you keep your saw so clean? You have probably already checked the alignment of your sprocket and the rails. Also, on one bar I have, one of the sprockets appears to be off, at one position, the chain is snug, at another position (moving the chain), the chain is not snug. I don't recall you saying that you tried a different bar? Good luck clearing up the problem.

Jaxx

I had that happen once and it drove me insane trying to figure it out. Turned out to be a bar that was slightly bent ... I got a new one and it solved my problem. I thought the clutch/drum/sprocket might be bad, the chain might be hitting the plates and sticking, and a lot of other stuff before I discovered that the bar was the cause of my issue.

 

[Highclimber OR]

From over here, I see two possibilities of your problem. It may be that your chain is one drive link too long. If so, this brings the tail of the bar too far from the sprocket causing the chain to derail as it enters the bar groove. This can be aggevated by a small tail on the bar and too big of a sprocket.
Try the smallest sprocket available or if you can change over to 3/8 then things may smarten up.
John

I have ran into this problem myself with the Stihl MS-260. Good call Gypo. Beyond that I would just get a new bar and see where that takes me.

 

[SawTroll]

I am having trouble throwing the chain off of my 488. The first day I used the saw it threw the chain off. I have had other saws throw a chain once a while, but this saw has done it to me several times and once today while felling a tree. I try to keep my chain tight enough to where there isn't any sag in the chain on the lower side of the bar, but maybe that isn't tight enough? I am running a 20" bar ( that is what the saw came with) and .325 x .050 chisel chain. I have noticed that while sawing, the chain looks as if it is lifting up on the top side of the bar. Any ideas?

Back to the simple stuff;

Was this with new chains?

They need to be readjusted more often than a run-in one (have been there umpkin2........

 

[HiOctane]

I think Gypo got it right.Not related to your chain problem,but i noticed on one pic that your lower a-v rubber was"off center" in the crankcase hole,meaning probably that your handle is bent .It makes your saw vibrate more.

 

[Poley4]

Back to the simple stuff;

Was this with new chains?

They need to be readjusted more often than a run-in one (have been there umpkin2........

Troll,
Yes, all three chains were new. I have been retentioning the chain after each tank of fuel as needed. I am just wondering now if it is more critical to keep the chain tight for the .325 x .050 chain on a 20'' bar compared to say the .375 pitch chain on my Stihl 036. I don't recall ever throwing the chain off that saw, but i don't use it much for limbing either.

 

[Poley4]

I think Gypo got it right.Not related to your chain problem,but i noticed on one pic that your lower a-v rubber was"off center" in the crankcase hole,meaning probably that your handle is bent .It makes your saw vibrate more.

HiOctane,
That rubber piece you are looking isn't an a/v mount. It is what Shindaiwa calls their "rubber covered chain catcher". Trust me it doesn't work very well, it looked like that after the first thrown chain. I was thinking about making me a new one on the lathe out of delrin or aluminum.

 

[SawTroll]

Troll,
Yes, all three chains were new. I have been retentioning the chain after each tank of fuel as needed. I am just wondering now if it is more critical to keep the chain tight for the .325 x .050 chain on a 20'' bar compared to say the .375 pitch chain on my Stihl 036. I don't recall ever throwing the chain off that saw, but i don't use it much for limbing either.

I don't really know, but there may be a reason that Stihl over here doesn't want to sell .325 .050 at all, and anything more than 15 or 16" is .063.

...but on the other side, I suspect that they have got the whole thing wrong, as anything except the drive tangs should be the same, for all gauges, for the same basic chain model.....:bang: :bang:


Bottom line, with new chains, retentioning every tankful is definately not often enough, at least not for the very first tankfull.

If the problems stays after that, the reason is probably something else.....

Take a look here, page 34 for starters.