Husky 576 Autotune Repair

[Brewz]

Hi Folks

I have a 2010 Husky 576 Autotune here that I was told had cactus poison mixed with the fuel in stead of oil.



I just got the top end off and the piston is scored up at the exhaust port but the rest of it looks ok.
N0t much oil in there but a little bit, ebough to keep the bearings nice.
Perhaps it shut down before it had a complete meltdown?

Found some nice buildup in the carb



Anyway, I have a few questions for the Husky heads out there.
1. Will 372 crank seals fit this saw?
2. Can someone in the USA get me a price on an OEM piston? They will be $200+ here in Oz

I bought a "quality aftermarket" piston from HL Supply and it turned up as a Golf
@Gentleman , would it be possible to have these pistons listed with their brand when known? and while I have you, can you sell an OEM piston on its own as I notice you have full OEM piston/cylinder kits listed.
I will be able to fix the cylinder... blame @Mastermind haha

The transfer cutouts on the Golf are different by a LOT and will dramatically alter the timing
It is also over 12% heavier

OEM @110g



Golf @ 124g



Check out the height difference of the lower cutout's top edge and the size of the top slot.
Its not even close.
Its a paperweight considering this saw is a business owned working saw.

 

[Marshy]

I beliwve the clutxh side bearing has an integrated seal. You cannot simply use a seal from a 372xp. That bearing is rather expensive.

 

[Gentleman]

would it be possible to have these pistons listed with their brand when known? and while I have you, can you sell an OEM piston

I will work on that. I will ask a friend if he can send me an OEM piston.

 

[Crzybowhntr]

@Brewz , I may have the block of plates needed to do pressure/vacuum tests. If you need them and I still have them, I'll send them out to you at no charge.

 

[Marshy]

Hi Folks

I have a 2010 Husky 576 Autotune here that I was told had cactus poison mixed with the fuel in stead of oil.

View attachment 46834

I just got the top end off and the piston is scored up at the exhaust port but the rest of it looks ok.
N0t much oil in there but a little bit, ebough to keep the bearings nice.
Perhaps it shut down before it had a complete meltdown?

Found some nice buildup in the carb

View attachment 46835

Anyway, I have a few questions for the Husky heads out there.
1. Will 372 crank seals fit this saw?
2. Can someone in the USA get me a price on an OEM piston? They will be $200+ here in Oz

I bought a "quality aftermarket" piston from HL Supply and it turned up as a Golf
@Gentleman , would it be possible to have these pistons listed with their brand when known? and while I have you, can you sell an OEM piston on its own as I notice you have full OEM piston/cylinder kits listed.
I will be able to fix the cylinder... blame @Mastermind haha

The transfer cutouts on the Golf are different by a LOT and will dramatically alter the timing
It is also over 12% heavier

OEM @110g

View attachment 46836

Golf @ 124g

View attachment 46837

Check out the height difference of the lower cutout's top edge and the size of the top slot.
Its not even close.
Its a paperweight considering this saw is a business owned working saw.

View attachment 46838

I thought I read the upper slot in that piston isn't used for porting fuel in the cylinder. Some things I read concluded it was for weight reduction. I have not confirmed any of that though. Maybe so some knows the first hand and will chime in.

 

[awol]

Don't be scared to use that Golf piston, I installed one last summer in a 576 for a local crew, and it runs every day. The top cutouts in that piston are only for weight reduction, they don't play a part in scavenging. The only way to check strato timing is to slide the piston up in the bore, and observe the ports opening. Mine was identical to an OEM in timing, but I did do a lot of grinding to change it to what I wanted.

 

[Gentleman]

OEM piston

I can get an OEM piston for around $65. Let me know if you want me to order it.
I'll credit you for the Golf if you don't want to use it.

 

[Brewz]

I can get an OEM piston for around $65. Let me know if you want me to order it.
I'll credit you for the Golf if you don't want to use it.

I respect awol's experience so I will use the Golf. If the top slot is for weight reduction only I will put it on a diet.

@Gentleman thankyou for the kind offer but I would only ask you for credit if I could send it back.

I will give the golf a go.

 

[Brewz]

Right!
Time to put this fat girl on a mill and deemel diet.

 

[Marshy]

Pics!

 

[Brewz]

Managed to take several grams out of the piston.
It's now only 4 grams heavier than OEM with most of that in the thicker walls.

I will be shortening the OEM wrist pun also as it's 25% lighter than the after market pin

 

[mdavlee]

Managed to take several grams out of the piston.
It's now only 4 grams heavier than OEM with most of that in the thicker walls.

I will be shortening the OEM wrist pun also as it's 25% lighter than the after market pin

View attachment 47032

View attachment 47033

View attachment 47034

1mm up an d1 mm down makes a decent runner from those with a thinner gasket.

 

[Brewz]

Up and down where mate?

 

[mdavlee]

Up and down where mate?

Intake and exhaust.

 

[mdavlee]

Muffler mod and I think the up 1mm and down 1mm is all that was.

 

[awol]

Some of them have room to drop the base gasket, that wohld give you 1mm down for the intake. They do reallly like a wide open muffler.

The grinding you did on your piston looks real similar to what I did.