macculloch chainsaw does not cut straight?

I have the same problem. Bought a MAC 7-42 and after a few cuts it started to pull to the left before the bar got stuck. I noticed that the chain had become loose, which if you digest every word in the manual it does warn. I tightened the chain, but it still cut to the left, so I took it back and got a replacement. Same thing happened with the replacement chainsaw. I think what is happening is that if you don't catch the moment the chain starts to become loose as it expands, and continue to force the chainsaw to cut, it knackers the chain.

You can try and file the chain so that it is even on both sides. Or buy a new chain. You might even need to get a new guide bar if it's become damaged by making curved cuts.

d4
September 2009

Easier check before all that effort would be to check the AV mounts

pleasant
September 2008

This can be caused by a badly sharpened chain - left and right cutters not balanced.
Otherwise a worn bar where the chain guides are not supported properly, allowing the chain to rock.
Try investing in a new bar to go with your new chain!
Some say you should replace bar and chain together.

J. Beaver
September 2008