Strange chain tension issue.

[Mark_Skyland]

Had a customer drop in yesterday with a 562XP. Basically as soon as you tighten the bar nuts the chain gets really tight, slacken the nuts of a tiny bit to get the tension right and the chain moves around the bar by hand nicely, tighten the nuts down and it hardly turns. I only had a quick look at it, bar and chain are matching, it had the same issue with his old bar and chain, nothing seems to be out of place in regards to the chain getting pinched, the drum isn't contacting the sprocket cover although the clutch springs are really slack but they didn't cause tick over issues which I thought strange, and there didn't seem to be too much movement in the clutch bearing and the guide plate looked OK. I will have a proper look over it next week starting by swapping out the sprocket cover to rule out any issue with that. Im thinking that somehow the bar is somehow twisting causing the issue.

 

He also said that he seems to be replacing the rim sprocket more often than usual, the rim floats freely on the drum.

 

Has anyone came across this issue before? 

 

 

[Pete Mctree]

The needle bearing could be damaged- had similar before and took me a while to work it out

[Mark_Skyland]

Thanks Pete, Ill check it out.

 

I suggested that he keeps the bar and chain and replace everything else, he didn't seem too keen on that option

 

 

[kram]

Whe  the nuts are slackened a tiny bit, is the bar lifting up away from the saw, if somethings bent so its not sitting correctly until fully tightened, that will do it.

 

With saw on its side, slacken nuts, adjust tension, press down on the tip of bar, whilst somone holds the saw and see if tension changes.

[Tree monkey 1682]

13 hours ago, Mark_Skyland said:

Thanks Pete, Ill check it out.

 

I suggested that he keeps the bar and chain and replace everything else, he didn't seem too keen on that option

 

 

Whats the side casing made out of? I know my 350 (different saw ) used to do funny things if the side cover was warped dont know if its worth having a look- and mine didnt show signs of internal damage either... 

[Mark_Skyland]

18 hours ago, kram said:

Whe  the nuts are slackened a tiny bit, is the bar lifting up away from the saw, if somethings bent so its not sitting correctly until fully tightened, that will do it.

 

With saw on its side, slacken nuts, adjust tension, press down on the tip of bar, whilst somone holds the saw and see if tension changes.

I'm thinking that it might be something like that causing the problem.

 

7 hours ago, Tree monkey 1682 said:

Whats the side casing made out of? I know my 350 (different saw ) used to do funny things if the side cover was warped dont know if its worth having a look- and mine didnt show signs of internal damage either... 

Its metal. I have a few old ones knocking about from knackered 550/560s so I will swap it out.

 

 

[Muddy42]

A worn sprocket can cause symptoms like this.