chainsaw twists clockwise as its cutting thru log - followup bar questions

First post here, so let me first of all thank every contributor for the enormous amount of excellent information available, I have been reading my way through a few hundred posts these last 2 weeks and gained some valuable tips. I initially found this site searching for Holz Hausen pics having learnt to build one from thechimneysweep.ca but obviously there is so much more going on here in the forums!

I have a Husky 353 chainsaw with 18" bar and recently broke a chain and bought a new one. The old one was the factory fitted (husky?) chain, the new one is a Stihl Oilomatic3 <edited as originally I thought it was Oregon> chain from my local dealer. I have noticed the new chain pulls me thru a log and twists to the left, or twists the saw clockwise as it cuts, compared to the old one. Such that if I was cutting thru a 12" log it would be 10 to 15 degrees away from vertical by the finish - halfway to "one oclock" on an hour hand.

Can anyone tell me why, and hopefully how to fix it? I wouldn't call myself a pro lumberjack by any stretch, but I've felled, limbed and bucked about 20 small trees lately (estimate 8 to 10 cords) and I certainly do start my cuts vertically, and I didn't have this problem with the old chain. I was wondering if the chain was the wrong type for the saw, or perhaps some sort of anti-kickback model and that's one of the disadvantages of them.

Also, whilst on the topic, I notice the new chain gets blunt a lot quicker than the old chain. A lot of our wood (I'm from Oz) is pretty hard, for example ironbark is well named, it's organic steel, rates about 73 pounds per cubic foot density or 14+ on a hardness scale (I don't know how hard North American woods are having never sawed them but I see from this site's reference article Hickory tops the list at 50 pounds per cubic foot, not sure if that translates to hardness, but if it does then our eucalypts like ironbark are around 50% harder and heavier). Is there harder steel chain eg perhaps Stihl chain the Husky may have used, that I can get instead that will hold sharpness longer? I saw a reference to this possibility in a recent Eric Johnson post of his visit to the Oregon Saw Chain company.

Backroads said:

Why did the chain break? Did by chance you damage the bar or not rotate the bar on a regular basis? If the bar is tweeked that could explain it possibly.

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Ahhh, that's an excellent question. I don't know is the short answer . . . I was rotating the bar with every chain sharpen on the old chain. The chain was getting worn, when I got the last (shop) sharpen done I was told it would be the last sharpen (as it turned out they were correct ) but it wasn't to the wear mark on the tooth yet.

I have been sharpening my new chain by hand file, just touching up the teeth every tank or so, but it was pulling that way from new. I've had a look at the bar and to the naked eye it looks fine. Should I pull it off and run a straight edge over it?

FIREFIGHTER29 said:

First off, welcome to the forum! There are a few reasons why your saw may be cutting this way. It could be anything from a worn out drive drum to an improperly sharpened chain. If your bar is warn out it could also cause this I suppose. When you broke your last chain, did you pinch the bar and or what happened to cause the chain to break? And was the saw cutting correctly prior to replacing the chain?

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Thanks - it's great to be here

I didn't pinch the bar when it broke, in fact I was sawing through a pretty small log using the teeth at the base to hold it, so cutting with the underside of bar and back half (nearest me / nearest motor) and it was well chocked and free falling so no chance of pinch.

Should I replace the bar with every chain? Or replace the drive drum with every chain? Or the toothed wheel on the bar?

The tilting pull happened from new chain, immediately, so can't have been a bad sharpen, and it wasn't happening with the old chain even in the minutes before breakage.

I don't know what caused my old chain to break, I just assumed with wear they eventually broke. I certainly got full life usage out of that chain, I reckon it started with 8mm of tooth to the wear line and finished with less than 1 mm to the wear line

Maybe I keep my chain too tight? I dislike the chain being too loose, I tighten it until I can - just - rotate chain by hand, and when lifting the chain the bits that are supposed to stay in the bar groove don't come out far enough to see daylight between them and bar.

Adios Pantalones said:

If you're just touching up teeth and not taking care of the depth settings- it could cause this. I solved the same issue a few years back just by taking down the depth.

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That might be the case for older chain, but it shouldn't be the cause with brand new chain (should it?) which is when mine started.

Same for left side vs right side sharpness, it is a good explanation and one I will remember for an older chain, but it shouldn't be the case with brand new quality chain (should it?).

Also from an earlier post, I watched the linked Stihl video (very helpful, thanks) and I was tensioning, not over tensioning, my chain correctly all the time. I'm just picky about it, not letting it run loose like some others do around here (my neighbours, not this forum).

I think the best explanation that I will check out is a worn drive drum, or damaged bar I can't see with naked eye, needing a straight edge and removal from saw. Thanks all for your feedback though, much appreciated!

OK, I have done some of what was suggested . . . first off, I am a bit embarrassed, but the chain is not oregon, it's Stihl. When I bought it I brought my old chain to the dealer and told him my model of chainsaw (Husqvana 353) and he looked up an Oregon Chain Catalog in front of me, then went and got the chain, I just grabbed the box with a few other bits and pieces and went home and fitted the chain, which is why I thought it was Oregon. Sorry

So, for what it's worth, the chain is a Stihl Oilomatic3 .325 with "5" on the guide/bar slot "tooth". I'm not sure how much attention to pay to the box it came in, as the box has listed 40cm/ 16inch for length of chain, and my husky saw has an 18" bar (it says on the bar and I measured it so I'm sure of that!). However, in case the rest of the box info is correct - I wouldn't know either way - the numbers from left to right are:
3610 000 0055 61 PMMC3 55
and under that:
40cm 16In | 55 | 9,32mm 3/8" P | 1,1mm ,043 In |

The first is clearly bar length and has a pretty pic of a bar, the 2nd has a pic of the bar guide tooth (sorry not sure of technical term, the one on the inside of chain that runs inside the bar slot) and the third is clearly 0.325" which matches the chain marking and has a pic showing it's the length between rivet in front of guide height and rivet below cutting tooth, whilst the 4th has a pic of thickness, but exactly what I can't be sure, perhaps thickness of bar slot tooth?

I inspected the bar and it had a small burr on the top near tooth wheel at end of bar. I find it hard to believe it could do anything, as I never cut with that part of the bar - it's prime kickback territory - but I filed it and flipped the bar and re-assembled after a good clean.

Whilst cleaning, I noticed something else - the inside of the bar (left side as you hold the saw) was worn with the "Husqvana" logo almost gone whereas the outside has the Husqvana logo in very good condition. To match, the inside rivets and chain in general was very clean, with teeth quite polished, whereas the outside was quite dirty with bits of gunk on the teeth and the rivets and chain covered in gunk. So clearly, the inside is getting wear or rubbing on the log on the way through. This doesn't make sense to me as the inside of the bar/chain is on the inside of the curve I am creating (unintentionally, I'm just holding the saw!) and therefore I would have thought it would get less abrasion or chafe compared to the outside. <sigh>

Anyway, I took some pics and will try to upload them later after cropping and re-sizing.

I haven't had a chance yet to cut with the bar reversed, but it's a good suggestion, I will do it as soon as possible.

[b]Pics:[/b]

The bar looks straight to me:




Inside of bar is chafing and Husqvana logo and name almost gone.



Inside of chain is very clean with almost polished rivets and cutting teeth:


Whereas the outside of chain is dirty with gunk all over it:


The log end showing the curved cut:

DiscoInferno said:

If it's actually .043" gauge (drive-link thickness) and the bar is .050" gauge (or larger), then as previous posters suggested the chain will be too loose side-side in the bar and that could certainly explain some crooked cutting. Compare the thickness of the drive links (bar guide tooth) on the new and old chains, and see if the new one can slop around in the groove.

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I gave the old chain to the dealer to dispose of - it was well worn and worthless to me - so I can't check that unfortunately. It's a good idea, but I don't have an old chain to put on and check. Maybe I should buy a second chain and ensure it has a .050" guage or whatever matches the Husky 18" bar and see if that fixes it? That was I'll have a spare / second chain. Then if the new chain does the same thing (with the bar flipped bear in mind) get a new bar or check something else. If it cuts straight with the new chain and flipped bar, I can use the current chain limbing and bucking small logs where the curved cut doesn't matter so much.

Thanks for all the replies and suggestions. I did actually take it back to the dealer this afternoon, wondering if he had sold me a chain with too narrow a guage for the bar. First of all he decreed the problem was because one side's teeth were sharper than the other sides. I discounted that immediately as it was happening from first use of brand new chain. I told him the box didn't match the chain, but was it possible he had sold me less than 0.050" guage chain? He said impossible, as the chain I had didn't come in less than 0.050", which I found strange, as the (incorrectly matched) box the chain came in has 0.043" on it. Hmmmm . . .

However, I took him at his word that the chain he sold me was 0.050", after all it has a "5" on the bar guide tooth, and he had a good look at the bar and picked up something I had missed, but similar to what others here have been getting at with the focus on chain guage.

The bar has been overheated along one edge (the top edge now it's flipped, formerly the bottom since I got the new chain) and allows more movement of the chain laterally than it should have. Which is similar to having too small a guage chain in the bar. So when it overheated it must have slightly widened the bar slot along that edge. Which makes me wonder if that is what caused the old chain to break (as an earlier poster asked). So a couple of follow up questions:

1) Can I repair the bar by filing it down, presuming the widening of the slot decreases away from the edge?
2) Or should I just buy a new bar? The dealer says it isn't a safety issue, I'll just keep cutting curves
3) Why did it overheat and how can I prevent this in future?

With #3, where I live in Australia it is pretty mild really, especially compared to the awesome winters I see in North America or Europe. Nights get down to 0 occasionally, more likely 2 or 3 degrees, no snow, frosts are rare. Days are great, often mid teens even in winter (now), nice and sunny. All temps are Celsius I have a chainsaw routine where every tank I finish, I stop, refuel and re-lube (which is never empty, the husky is cleverly designed to ensure lube outlasts fuel), run a file across the teeth holding the bar in a gloved hand for a light sharpen but my wood shavings are always beautiful long peelings, and have a drink and maybe take a picture. So even with constant work through a long 10 or 12 hour day, which I've done a few times, I can't see how I'm overheating a bar. The chain always looks lubed and never feels hot when I sharpen it. Any ideas on how I have overheated and not noticed, and what do I look for in future to avoid this?

Thanks so much for all your advice so far!