Husqvarna 550XP intermittent power mystery.

[adw]

No, they have conventional seals, however I have seen collapsed bearing cages on the drive side so the crank has up and down play which makes the seal leak.

[spudulike]

All two strokes can suffer in this way but the 372 bottom end is a pretty tough cookie. Not seen many issues with it but you can get slight air leaks on the clutch side but a new seal generally fixes them.

Worth getting the saw pressure and vacuum checked if it has just started happening but you may get over it with a carb retune although this may just possibly mask other issues.

I have found the XT version to sometimes have an unstable idle and personally think the coil fitted on these machines had a different advance coming off idle than the earlier XP version. It can backfire on starting which supports this theory.

 

[htb]

• Thanks to both of you will have a look and see what its doing, have already changed throttle cable as apparently they can snag.

[spudulike]

You can pop off the top cover and the air filter then rev the engine and push the throttle closed with the carb mechanism rather than the throttle and that should tell you if you have a throttle linkage issue.