Husqvarna 51 Needs New Piston/Cylinder and TLC

[IH1972]

There's a chance that the oem cylinder will clean up with some scotchbrite . I got a 55 that the piston was heavily scored, I thought the cylinder was too. It took a little work but I got it cleaned up, you can still see a couple score lines in it but you can't feel them with your fingernail. I put a meteor piston with caber ring in it and it runs very good.
The best advice I can give you is Don't fix this saw. If you do and it runs good, you are going to want another and another and another. You will have CAD like most of us here and there is no known cure.

I've seen a video on YouTube where a guy was able to resurrect a 51 with a bad piston, but salvaged the cylinder. I'll inspect it when I get it taken apart to get an idea if that may be an option for me.
The nice thing about chainsaws is that they are a lot cheaper than a car or truck addiction.

 

[Stump Shot]

I'm not scared as I already have a OP 51 and like the saw, but my closed port 55 runs a little stronger.
I guess what I am attempting to say is a open port 55 is pretty close to a closed port 55 because of the bore diameter change up deal.

 

[IH1972]

That makes sense. I may hunt around and see if I can source a closed port OE P&C.

 

[82f100swb]

Stay away from the Hyway/Meteor closed port jugs. They just closed in the open port, and they do not have proper transfer port shapes. It's a struggle to make them run as good as stock.

If you want to hunt for performance, you want a Partner 5000/Jonsered 490(44mm) or Partner 5000/Jred 590(45mm) cylinder. They are harder to find, but they are the best bolt on cylinders you can get on this chassis.
The closed port 55 45mm cylinder carries the same casting number as the Partner/Jonny one, but it has a larger combustion chamber, and isn't ported nearly as hot as it existed more for emissions reasons.
The 46mm Partner 5500/Poulan 325 cylinder, besides being impossible to find, is also a large chamber design, and my 590 outruns my 325 every time.

Lots of guys have built very stout saws using the open port cylinders, I would take one over the Hyway/Meteor CP top end any day of the week.

 

[IH1972]

Stay away from the Hyway/Meteor closed port jugs.

If you want to hunt for performance, you want a Partner 5000/Jonsered 490(44mm) or Partner 5000/Jred 590(45mm) cylinder. They are harder to find, but they are the best bolt on cylinders you can get on this chassis.

The closed port 55 45mm cylinder carries the same casting number as the Partner/Jonny one, but it has a larger combustion chamber, and isn't ported nearly as hot as it existed more for emissions reasons.
The 46mm Partner 5500/Poulan 325 cylinder, besides being impossible to find, is also a large chamber design, and my 590 outruns my 325 every time.

Lots of guys have built very stout saws using the open port cylinders, I would take one over the Hyway/Meteor CP top end any day of the week.

Stay away from the Hyway/Meteor closed port jugs.

If you want to hunt for performance, you want a Partner 5000/Jonsered 490(44mm) or Partner 5000/Jred 590(45mm) cylinder. They are harder to find, but they are the best bolt on cylinders you can get on this chassis.

Lots of guys have built very stout saws using the open port cylinders, I would take one over the Hyway/Meteor CP top end any day of the week.

It sounds like an OE P&E may be my best option unless I can come up one of the above cylinders. If I can find one, which pistons get paired with them, or are they sometimes found as a P&E set?

What modifications would you suggest to improve the stock open port cylinder saw?

Thanks for your input.

 

[5155]

One mistake I made was using a quality fuel line that was NOT oem.
The ID was right, but the OD was too big and choked the line at the grommets.

 

[IH1972]

One mistake I made was using a quality fuel line that was NOT oem.

I'm definitely going to use OE fuel line.

 

[drf256]

Will a 262 P&C fit this saw, like it does a 257?

 

[ammoaddict]

Will a 262 P&C fit this saw, like it does a 257?

That would be interesting. They share the same tank handle but the intake is different. It wouldn't be a direct swap but it might could be done. I hope someone replies that knows. I would do my 55 if it could be done without a lot of modifications.

 

[smokey7]

If I want a closed port cylinder, the only option appears to be aftermarket. Of course I'd rather have an OE piston/cylinder, but those are now NLA.
This saw is going to be a play/learning saw as I have other work saws, so I may try to find a closed port Meteor kit. I've read that they might be slightly higher quality than Hyway.
In the meantime, I'll read up on ignition advance.

The closed 55 cylinders from any aftermarket supplier for ms390s and 51 and 55s have been normal open port castings that they put a closed port divider in. So in my minds eye they will probably run worse then the normal open port.

 

[82f100swb]

That would be interesting. They share the same tank handle but the intake is different. It wouldn't be a direct swap but it might could be done. I hope someone replies that knows. I would do my 55 if it could be done without a lot of modifications.

The commonality ends at the tank and handle. The 257/262 are 154 chassis saws, with a long connecting rod crank, so you can't even put either top end on a 154/254. All of them are 34mm stroke.

The 50/51/55 share crank/flywheel/clutch, intake and piston/cylinder with the Partner 500/5000 family.
You wanna go fast with this chassis, you need Partner/Jred(490/590) parts. They are direct bolt on as well.
Stroke is 32mm.

The closed 55 cylinders from any aftermarket supplier for ms390s and 51 and 55s have been normal open port castings that they put a closed port divider in. So in my minds eye they will probably run worse then the normal open port.

That is exactly what they did, and it takes a pile of work, even with an 028 Super piston and 260psi of compression to make it stronger than a stock open port saw. I have that T-shirt

 

[Spike60]

How is this project coming along?

@82f100swb has all the various options impressively nailed down. I do have a 51 with the 490 kit, and it's a quick little saw. The Partner/Jonsered top ends are hard to find, and while they do run well, it's not as if the saw isn't worth building without one. Best of the rest is the 46mm 55 kit. They all respond well to the basic mods.

In fact I've always wondered why these saws are mostly overlooked here in hobby land. The are simple, reliable, good runners that were made in large numbers. There's tons of them lying around and can be had for little or no money. Easy to work on. They deserve more love than they're getting.

 

[ammoaddict]

How is this project coming along?

@82f100swb has all the various options impressively nailed down. I do have a 51 with the 490 kit, and it's a quick little saw. The Partner/Jonsered top ends are hard to find, and while they do run well, it's not as if the saw isn't worth building without one. Best of the rest is the 46mm 55 kit. They all respond well to the basic mods.

In fact I've always wondered why these saws are mostly overlooked here in hobby land. The are simple, reliable, good runners that were made in large numbers. There's tons of them lying around and can be had for little or no money. Easy to work on. They deserve more love than they're getting.

I love them. I will take all I can get for cheap.