590 jonsered

[manostihl]

I'm planning on rebuilding my tired old 590 this winter and I was wondering where I can get a piston and possibly a cylinder as well depending on the damagei was thinking about hot rodding it a little as well are there and big bore kits or any bigger j red cylinders that will bolt on ??? Will post pics tmw

 

[rbmopar]

I'm not aware of any pistons than will swap into a 45mm 590.

 

[SawTroll]

Those closed port 45mm topends will be hard to find.

 

[spike60]

Those closed port 45mm topends will be hard to find.

If not impossible.

Just a guess, but would a 254XP piston work in a 590?

 

[manostihl]

Those closed port 45mm topends will be hard to find.

damn that is not wat i was hoping to hear i tried ebay but got nothing ....this is a really great cutting 50cc saw....id hate to put her on the shelf for good :msp_mad:

 

[RedneckChainsawRepair]

If not impossible.

Just a guess, but would a 254XP piston work in a 590?

I'm thinking I was told the wrist pin on the 254 was bigger then 590 at one time. Not sure with my memory anymore though.

Yep found it in the thread where we were talking about this last year. 254 has 12mm pin and I think 590 is 10mm (not sure there again).

 

[manostihl]

here she is View attachment 248576View attachment 248577

 

[Arrowhead]

I have 2 590's. Ones perfect, the other needed a piston. I just found a piston 3 days ago. It took me over 2 years to find.
Open port pistons are available, but the closed ports are hard to find.

 

[Chris J.]

:dunno: I've read something here about the Partner 5000+ topends, but I'm thinking they work on the Jonsered 490, not the 590.

 

[RedneckChainsawRepair]

 

[SawTroll]

:dunno: I've read something here about the Partner 5000+ topends, but I'm thinking they work on the Jonsered 490, not the 590.

I think they will fit on both, but I don't know for sure.

 

[rbmopar]

View attachment 248606 Here's a new 590 top end I found a while ago. The lip on the cylinder that goes into the crankcase is 50mm on the 590, and 48mm on the 490/5000. To put a 590 jug on a 490/5000 you have to open up the crankcase. I don't see any problems putting a 490 jug on a 590, but have never done it.

 

[manostihl]

is the partner top end better?

 

[Arrowhead]

Between Partner 500/5000, Jred 490/590, Poulan 325 I have over 20 of these saws. (my favorite smaller saw)
The Partner 5000 closed port is the identical to the Jred 490. The 590 is better in my opinion... same compression (my running 590 has almost 200lbs) same port timing, the 590 is 45mm and the 5000+ is 44mm. Many people think a Husky 55 45mm closed port is the same as a 590. It is not, they use the same mold, but the Husky's have different timing numbers and a larger combustion chamber. They are still good, just not as hot as a true 590 top.
In my opinion the 325 Poulan/Partner 5500 is king of these style saws. At 46mm and basically the same timing numbers, they rock.

ModifiedMark is the only person I know with a 5500 Partner. :drool:

 

[manostihl]

is this the open and closed port piston ???? whats the difference

 

[manostihl]

i think id like to do some serious portwork to the 590 if i can get a piston :cool2:i guess ill jus have to tear her down when i got the money and see what i got to work with

 

[Arrowhead]

is this the open and closed port piston ???? whats the difference

Both are closed port. The 5000 on the left uses a full circle piston skirt. The 590 on the right uses the more traditional style piston.
All 590's are closed port. Open port is a solid piston and the transfers are completely open on the cylinder. In the pic, the 590 jug appears to be an open port on that angle, but they are closed. They came with the skirt cut back from the factory.... at least most of them. One of my 590's has a completely skirted jug like the 490/5000.

 

[Stihl Crazy]

Open port is a solid piston and the transfers are completely open on the cylinder.

Usually, but not always. Some of the best running open port saws have open sided pistons pistons.

 

[Modifiedmark]

In my opinion the 325 Poulan/Partner 5500 is king of these style saws. At 46mm and basically the same timing numbers, they rock.

ModifiedMark is the only person I know with a 5500 Partner. :drool:

That opinion can be backed up with facts!

 

[manostihl]

That opinion can be backed up with facts!

will a 5500 top end bolt on ?