New chain binding when I tighten side plate bolts

[tewdric]

Hi folks.  I have fitted a new chain to my Husqvarna 545.  On reassembly the chain rotates freely with the bolts loose but when I tighten them it binds.  Chain brake is definitely off, chain is correctly sat on the rear sprocket, bar is straight and serviceable.  It’s a mystery!  I have checked I bought the right chain and it’s oriented correctly- I compared it to the old one and apart from cutting teeth obviously being longer they are the same.  Any ideas?

Edited January 13, 2024 by tewdric

[Stubby]

3 hours ago, tewdric said:

Hi folks.  I have fitted a new chain to my Husqvarna 545.  On reassembly the chain rotates freely with the bolts loose but when I tighten them it binds.  Chain brake is definitely off, chain is correctly sat on the rear sprocket, bar is straight and serviceable.  It’s a mystery!  I have checked I bought the right chain and it’s oriented correctly- I compared it to the old one and apart from cutting teeth obviously being longer they are the same.  Any ideas?

This may be obvious but do you raise the tip of the bar before setting the tension and tightening the bar nuts ? 

[pleasant]

Is it fitted with a rim sprocket? It's possible the drive teeth aren't located in the corresponding holes for them in the rim, so with the side cover loose it will allow the chain to move, but when tightened as the chain isn't correctly located it will clamp it up and not allow it to move?

[tewdric]

47 minutes ago, pleasant said:

Is it fitted with a rim sprocket? It's possible the drive teeth aren't located in the corresponding holes for them in the rim, so with the side cover loose it will allow the chain to move, but when tightened as the chain isn't correctly located it will clamp it up and not allow it to move?

Yes it is I’ll double check that thank you.

[adw]

I have seen things like this before, it may be worth removing the bar adjuster pawl, then take a flat file across the pad area of the side cover to remove any high spots on the corners of the pad.

[spudulike]

What happens if you tighten the side cover lightly so the bar can still be moved around but lightly clamped and then leave the chain a little loose and then tighten the cover fully? Does the chain tension up but still turn? 

[Haironyourchest]

I've had this before: Wrong drive link gauge. Oregano chain, 1.5 vs 1.6, you got 1.6 gauge in a broken-in 1.5 bar.

 

Or the sprocket thing.

[spudulike]

Not the Oregano again, best used on pizzas or pasta dishes and should be kept away from chainsaws.

[adw]

11 minutes ago, spudulike said:

Not the Oregano again, best used on pizzas or pasta dishes and should be kept away from chainsaws.

Behave, play nice.

[woody paul]

I had similar troubles with a 362, turned out to be aly plate on clutch cover had got bent out when I cleaned it before re assemble. 

Got no idea what on clutch cover but it' may have a plastic chain guide attached by screw check that it's nor come loose.