husky 576xpg autotune strange one

[MattyF]

My 576 became gutless after a filter clean on a job, would not run right at all... I changed the fuel filter which made a little difference but was under warrantee ,The dealer told me they reset the auto tune and that was all it needed and has ran fine since , it's a lovely saw but that knocked my confidence in it and out of the 6 saws I have with auto tune it's the only one to have played up.

[forest tink]

Worth checking the main bearings out and looking at the piston through the exhaust port as well!

 

Sounds like a mechanical issue but difficult to tell!

 

have had the exhaust of and all looks good in there,no obvious damage,had the clutch and oil pump out,looks ok that side,no play or anything,will check the flywheel fins shortly,hope its something simple but dunno at this stage,was thinking today,best way to describe the shudder is like a warped brake disc when you brake in your car,only difference being it goes through your hand and not your foot

[Sawchip]

Most has been said already but I wonder if there is a connection to something with the air filter cleaning. That was the time it changed from a runner to what you have now. Throttle Linkage …wire connection to carb or on off switch..sh&& into the carb when disconnecting filter...??? Im clutching at straws here but I would be re tracing your steps to the point it stopped behaving .

[forest tink]

yep just had a look at all that,seems all ok,changed the autotune unit and it has made no difference at all,flywheel has no play at all and all fins are intact,think tomorrow nights job will be to have the head off to have a better look in there,dont know if the the little bearing at the piston end would give it a wobble if it had collapsed or not,frustrating

[spudulike]

Pull the plug out and see if the saw is easy to spin over and there is no hindrance in the crankshaft. The coil isn't gunged up with wood chip is it?

 

One thought, from the XPG, it must have heated handles so would check the coil assembly around the back of the flywheel is still in place. It is possible the magnet has become detached from the flywheel or the coil power generator (not the ignition coil) has become loose!

[forest tink]

Pull the plug out and see if the saw is easy to spin over and there is no hindrance in the crankshaft. The coil isn't gunged up with wood chip is it?

 

One thought, from the XPG, it must have heated handles so would check the coil assembly around the back of the flywheel is still in place. It is possible the magnet has become detached from the flywheel or the coil power generator (not the ignition coil) has become loose!

 

crank feels nice and smooth when plugs out,pulls over well,good shout about the heated handles,will check the back of the flywheel tomorrow,thanks

[adw]

This is starting to sound like the drive side main bearing cage has broken up, or the bearing has come loose in the crankcase, grab the end of the crank clutch side and check for up and down movment.

[forest tink]

This is starting to sound like the drive side main bearing cage has broken up, or the bearing has come loose in the crankcase, grab the end of the crank clutch side and check for up and down movment.

 

have tried that on the clutch side,no play at all,will try the other side tomorrow

[amfell]

Have seen on a 550xp which is basically the same construction the 2 crank fillers have a plastic insert that partially melted and allowed them to rattle against the crank

root cause put down to a big-end bearing that nipped and over heated

1 replacement crank assembly later all sorted

[spudulike]

The XPG ones are always difficult to tell if the bearings are smooth due to the coils mounted on the crankcase at the back of the flywheel. It always makes them feel notchy.

 

It may be worth removing the flywheel so you can tell and if you take the cylinder off, any roughness will be evident as the bearings will be silky smooth and you should be able to spin the crank round at speed by lightly moving the little end up and down!

 

Move the crank ends up down and side to side to ensure those bearings are good - not always easy to tell for the novice but there should be no play evident!