Husqvarna 390XP blowing smoke from clutch area

[batemry]

Hi

My 2 year old Husqvarna 390XP is blowing smoke from the clutch area (which also ends up coming through the muffler).

Ive had 2 piston/cylinder replacements in the last 6 months (from apparently doing a too leaner oil:fuel mix - even though i always go under the recommended 50:1 mix).
Latest mix was 35:1, as many other operators are saying your better off using more oil then not enough (to stop the expensive rebuild from happening again with 50:1 mixes)

Anyway, the clutch cover was blueing from heat, and i also couldnt disengage the saw at all (presume clutch brake issue)?? When idling, the chain wasnt spinning though

Seems to be a bit of oil leaking around clutch area (think the adjuster screw may not be right). Some of blue plastic on the clutch brake was melted, so wondering if that caused smoke as well as the excess oil

Can anyone see any issues with the clutch from the below pics? Was going to give the bearing a grease whilst ive got it off

Thanks

 

[sean donato]

Either the brake was engaged, you're cutting with a very dull chain and forcing the saw to cut or the chain got bound up. Clutch looks severly overheated too. I'd suspect you have pto seal issues as well from how frued everything looks. Looks about the normal amount of oil slung around. Extra 2 stroke oil without tuning the saw doesn't do anything helpful. Adding more oil takes away from the fuel leaning the saw out, leading to having to ritchen the carb up to compensate.

 

[batemry]

Either the brake was engaged, you're cutting with a very dull chain and forcing the saw to cut or the chain got bound up. Clutch looks severly overheated too. I'd suspect you have pto seal issues as well from how frued everything looks. Looks about the normal amount of oil slung around. Extra 2 stroke oil without tuning the saw doesn't do anything helpful. Adding more oil takes away from the fuel leaning the saw out, leading to having to ritchen the carb up to compensate.

Thanks

Will this clutch still be fine to use? If not, how can you tell? Thanks

 

[cookies]

Thanks

Will this clutch still be fine to use? If not, how can you tell? Thanks

clutch drum is trash, clutch is likely trash, replace both and the bearing, you need to pressure/vacuum test the crank seals before returning it to work

 

[J D]

Whats up with the missing nylon spring catch block... if thats not there the brake won't be working as it should.

If the blue plastic spring retainer has melted it's been hellova hot in there... given it's gone through 2 top ends in short order I'd start by vac/pressure testing it (checking the piston at the same time)... if it does pass I still wouldn't have much faith in that clutch side seal (which is unfortunate as they are integral to the bearing on those), they can be ordered seperately but are expensive & no fun to replace.

 

[batemry]

Whats up with the missing nylon spring catch block... if thats not there the brake won't be working as it should.
View attachment 1192713View attachment 1192714
If the blue plastic spring retainer has melted it's been hellova hot in there... given it's gone through 2 top ends in short order I'd start by vac/pressure testing it (checking the piston at the same time)... if it does pass I still wouldn't have much faith in that clutch side seal (which is unfortunate as they are integral to the bearing on those), they can be ordered seperately but are expensive & no fun to replace.

The nylon blocks on both springs melted due to the heat.
Seems strange how it all just happened at once. Have had nothing but trouble with this saw. Hasnt done much work and is only a couple years old. Feels like i got a lemon

 

[J D]

Who's been doing the repair work?
Have you been using OEM parts?
Did it get Vac/pressure tested before & after it's rebuilds?
What was the reasoning behind blaming the mix for the earlier failures?
I'd check around the muffler for any leaks or damage... if exhaust is directly heating that area it would explain the melted plastic parts & those melted parts would cause the brake band to close up which would explain the clutch overheating

 

[batemry]

Who's been doing the repair work?
Have you been using OEM parts?
Did it get Vac/pressure tested before & after it's rebuilds?
What was the reasoning behind blaming the mix for the earlier failures?
I'd check around the muffler for any leaks or damage... if exhaust is directly heating that area it would explain the melted plastic parts & those melted parts would cause the brake band to close up which would explain the clutch overheating

Just the local Husqvarna dealer mechanic. Not sure if they did that. I presume that'd be standard practice?

They sent the piston to Husqvarna and they said it was obvious it was a dry seizure from lack of oil in mix, which I couldn't believe as I always use the Husqvarna oil mix bottle that measures it exactly to make 50:1. See pics of scorned piston

 

[bwalker]

Just the local Husqvarna dealer mechanic. Not sure if they did that. I presume that'd be standard practice?

They sent the piston to Husqvarna and they said it was obvious it was a dry seizure from lack of oil in mix, which I couldn't believe as I always use the Husqvarna oil mix bottle that measures it exactly to make 50:1. See pics of scorned piston

That's a lean seizure, not a straight gas seizure. Pressure and vacuum test, but I would bet it's a PTO side crank seal at minimum.

 

[sean donato]

I'd be finding a different dealer if the saw roached 2 top ends with them doing the work to it. They missed a leak, or didn't have the carb set right.

 

[Gord404]

with all that heat in the clutch area that pto sealed bearing could be hooped- leaking, I have rebuilt a lot of 390's and generally thats the first place I look when pressure- vac test- I find 2 things that cause leaks there is the sealed bearing itself or the crank not a good tight fit and if i'm stating a new build I replace it and the flywheel side bearing- not a good thing if you put a saw together and you find that bearing leaking.