Husqvarna 550 Big End

[muldonach]

I have just ripped down a 550 XPG that was cutting out on tickover and sounding pretty horrible under power - we pulled the exhaust off it and thought that the piston was scored but having stripped it down there does not look to be a lot wrong with it.

I did a compression check (cold) before stripping it down and only got 80 to 100psi. Having looked at a couple of youtube videos I should propably done a gross leak check before stripping it- I don't currently lhave a pressure test kit.

There is significant (maybe 1mm) up and down play on the conrod big end (pretty good sideways wobble as well but as I understand it that is normal) - I seem to recall reading that this is a failure point on these saws but did not find anything on a search of this forum

[adw]

You should have zero up and down movment on the con rod ( big end ) side to side movment ( lateral ) is acceptable, these saws are more suseptable to main bearing cages breaking up not so much big end bearing wear.