Husqvarna 365 replacement piston cylinder

[brisbane trees]

Hi

 

I have an old Husky 365 special that I pulled apart last night. The piston and cylinder definitely need replacing. Can anyone tell me whether I'd regret spending so little on Chinese replacement parts? They're so cheap.

 

Will I lose power? Interestingly, I can get a 52mm bore which is rather an upgrade from the 48mm original.

[spudulike]

Hi

 

I have an old Husky 365 special that I pulled apart last night. The piston and cylinder definitely need replacing. Can anyone tell me whether I'd regret spending so little on Chinese replacement parts? They're so cheap.

 

Will I lose power? Interestingly, I can get a 52mm bore which is rather an upgrade from the 48mm original.

 

What is wrong with the cylinder? Us it aluminium transfer or are there scores in to the cylinder.

 

The OEM part is generally much higher quality.

 

Do you know why it failed?

[Eddy_t]

Hi

 

 

 

I have an old Husky 365 special that I pulled apart last night. The piston and cylinder definitely need replacing. Can anyone tell me whether I'd regret spending so little on Chinese replacement parts? They're so cheap.

 

 

 

Will I lose power? Interestingly, I can get a 52mm bore which is rather an upgrade from the 48mm original.

 

 

The hyway kit is the better choice out of the big bore kits, although you will need to change the carburettor, as it will run very rich with the narrow Venturi

[brisbane trees]

What is wrong with the cylinder? Us it aluminium transfer or are there scores in to the cylinder.

 

The OEM part is generally much higher quality.

 

Do you know why it failed?

 

It's scored. It was my first bigger saw and I once ran it with cheap oil while spending a hot day cutting up a huge mango tree.

 

The hyway kit is the better choice out of the big bore kits, although you will need to change the carburettor, as it will run very rich with the narrow Venturi

 

Thanks, I see there are some available on ebay. Would you suggest a particular carby?

 

I saw another thread on this site about honing the bore and I'm considering whether I'd get away with that.

[spudulike]

It's scored. It was my first bigger saw and I once ran it with cheap oil while spending a hot day cutting up a huge mango tree.

Thanks, I see there are some available on ebay. Would you suggest a particular carby?

I saw another thread on this site about honing the bore and I'm considering whether I'd get away with that.

 

Everyone says that their bore is "Scored", a score is a gouge in to or through the NiSC plated bore.

 

Very often, the piston surface on the exhaust side has started to melt on to the cylinder bore, this then locks the rings in their grooves, compression lowers and the engine seizes.

 

Very often, this "Aluminium transfer" can be removed with acid or alkali to reveal a near undamaged bore underneath:thumbup:

 

To put it in to context, I have around a 98% salvage rate on seized cylinders that have gone like this.

 

You will find that the OEM bore gives a better piston to cylinder fit, the port timing is better, the port bevels are better and is generally far better manufactured.

 

Personally I always try to salvage the bore and fit a quality Meteor or OEM piston as this gives the machine a better chance of long term service after repair. The original cause of seizure should be found and rectified - if it was 100% bad mix then fine, it is done already but I always do a number of checks on a repaired machine to set it up correctly.

 

If all else fails, I would fit aftermarket and Hyway are not bad but you can't expect a £65 P&C kit to compete on life expectancy with a £300 Mahle kit!

[luftwaffe]

Not only do you know your stuff Spud, but you explain things so clearly.

[KevR]

Very often, the piston surface on the exhaust side has started to melt on to the cylinder bore, this then locks the rings in their grooves, compression lowers and the engine seizes.

 

Very often, this "Aluminium transfer" can be removed with acid or alkali to reveal a near undamaged bore underneath:thumbup:

 

 

Exactly what I found on the (free!) 281XP I acquired a few weeks back. The bore cleaned up really nicely. Bought a Hyway 2-ring piston kit, gaskets etc, and just got my new main bearings so it'll be going back together this week I hope.

[spudulike]

Not only do you know your stuff Spud, but you explain things so clearly.

 

Thank you dear Sir:thumbup:

[NFG]

Not only do you know your stuff Spud, but you explain things so clearly.

 

Hi

 

Agreed, +1 from me, thank you Spud.

 

Hope the OP gets its fixed, its a nice saw the 365

 

N

[brisbane trees]

Everyone says that their bore is "Scored", a score is a gouge in to or through the NiSC plated bore.

 

Very often, the piston surface on the exhaust side has started to melt on to the cylinder bore, this then locks the rings in their grooves, compression lowers and the engine seizes.

 

Very often, this "Aluminium transfer" can be removed with acid or alkali to reveal a near undamaged bore underneath:thumbup:

 

Hi, and thanks for replying. I can see you know your stuff, so please excuse me for making the most of it.

 

Would you mind suggesting what acid or alkali I should use to clean up the cylinder? Is there a set technique I should use? Would just rubbing it with vinegar possibly work?

 

Thanks very much.