chain spins off the bar.

[gdismine]

How come my 350 husqvarna keeps throw the chain? especially when I am cutting limbs and brush. I have checked tension. and even replaced bars and chains. I have tried sproket tips and hard nosed bars. Just can't figure out why it keeps spinning off the bar. Chain saw is always used at full throttle before touching wood.

 

[smokinj]

does your drive sprocket match the chain your using?

 

[cuttinscott]

That is the problem with .325" pitch chain the drive tangs are not embedded as deep in the bar rail as 3/8" chain would be...... This is WHY I sell 99% of the Dolmar PS460, PS510, and PS5100's wearing 3/8" chain..... So if and when the chain SNAGS on brush it easily becomes disloged from the bar rail with .325" also per bar length the .325 had more links and rivits to loosen than a 3/8" would......


OK Im done with my .325" vs 3/8" rant have at it.......





Scott

 

[gdismine]

Thanks Cyclone

B\Yes I checked the numbers for each, chain an bar and they were purchased as a set. I even bought a new hard top bar and chain set with no sproket and it spun off the same way. I have asked an aborist who uses Husqvarnas all the time and he never ran into this problem he checked my tension and he is confused as well. That is why I am posting here in the hopes of finding someone who has run into this problem before.

 

[smokinj]

B\Yes I checked the numbers for each, chain an bar and they were purchased as a set. I even bought a new hard top bar and chain set with no sproket and it spun off the same way. I have asked an aborist who uses Husqvarnas all the time and he never ran into this problem he checked my tension and he is confused as well. That is why I am posting here in the hopes of finding someone who has run into this problem before.

not talking about the chain bar combo where talking about the chain drive on the saw its self the drive sprocket!

 

[gdismine]

To cuttingscott thank you

Thanks for the response Scott. It sounds as if you had a similar problem. I never considered getting the 3/8 chain and bar set. I will give it a try.

 

[gdismine]

Smokin thanks again for the quick response

Cutting scott said something about the 3/8 chain . instead of .325. While looking at the 3/8 chain I can see it has a beefy chain . Ihope it will work.

 

[Paul001]

Thanks for the response Scott. It sounds as if you had a similar problem. I never considered getting the 3/8 chain and bar set. I will give it a try.

You need to verify which sprocket you have. If it's a .325 currently, you will need to change it before switching to 3/8's.

Second issue has to do with how you are cutting. I've had more than one guy work for me who couldn't keep a chain on to save their lives. Same saw, bar chain combo with another operator and it wouldn't come off.

Take a moment or two and think about how you were cutting when you lost the chain, was your angle something other than 90 degree's to the wood? Were you comming off the throttle? Did the tip catch another branch?

What is the common factor?

 

[smokinj]

Cutting scott said something about the 3/8 chain . instead of .325. While looking at the 3/8 chain I can see it has a beefy chain . Ihope it will work.

you can just change the drive sprocket and all is good

 

[371groundie]

you might try running your chain a little tighter. if im working in conditions that are likely to pull a chain off... (beech limbs, hemlock limbs, spruce limbs, cutting little brush.) ... i will snug the chain tighter that normal to help hold it on.

i assume you are having problems while limbing? look at the forces on the wood. you want to cut from the side that is under tension, not the one that is under compression. also cut stationary wood. if you are cutting out on the branch where it can wiggle it is more likely to pull a chain off that if you cut it next to the stem of the tree.

make sure that your bar and clutch cover are both seated properly. and make sure the sprocket has some side to side play on it. the sprocket is supposed to move to keep the chain in line with the bar. if they arent lined up, that could be the source of your issues.

 

[gdismine]

You guys are amazing.......

I got more info from all of you in two days then from my dealer and all the people I have talked to around me. Thanks from the bottom of my heart and I mean it. Thank you for your responses and your knowledge and the ability to share it with others in need. I have quite a bit of things to check out on the saw now. And I know I will be busy with it all. But I feel as if (with your help) I might just solve this. Thanks again and watch for falling limbs. :greenchainsaw:

 

[tbone1911]

Try this................

A couple of years ago I was having the same problem. What had happened was I had thrown a chain once while delimbing a tree. Unbeknownst to me I had burred up a few of the drive links in the process of getting my chain thrown. After that every so often whenever the burred drive links would try to get back into the bar after going around the sprocket the drive links would ride outside of the bar and derail.

 

[Gypo Logger]

The two biggest causes of derailed chain is the bar groove is worn way beyond the gauge of the chain,along with other worn terminal parts along with loose chain. Over tightening of the chain just compounds the problem.
Deburring of drivers is easy if done correctly, just loosen chain so it hangs, start saw and the burrs will come off, but be careful, Ive seen broken cranks when the burring was very severe and a driver caught at WOT.
YSM