Jonsered 590 rebiuld -PIC HEAVY-

[Nogoingback]

Besides it being 45mm no. Did you want height and other measurements? If I go back in to mill the jug I can take them.

Just wanted to ask if you are sure the cylinder is 45mm? I tore down a 590 last week to clean it up and get it running and when I popped the cylinder off I was surprised to see a closed port cylinder. The 490 is supposed to be a 44mm closed port and the numbers on the side of the cylinder had 44 cast into it the same as yours. Every source of info for the 590 I found showed it having a 45mm open port cylinder. I was thinking someone did a cylinder swap on mine at some time and was hoping it was a 490 cylinder. Supposed to be a hot rod of a saw.

 

[dk27]

the saw I'm trying to i.d. is a 45 mm ,closed port.

 

[Arrowhead]

Just wanted to ask if you are sure the cylinder is 45mm? I tore down a 590 last week to clean it up and get it running and when I popped the cylinder off I was surprised to see a closed port cylinder. The 490 is supposed to be a 44mm closed port and the numbers on the side of the cylinder had 44 cast into it the same as yours. Every source of info for the 590 I found showed it having a 45mm open port cylinder. I was thinking someone did a cylinder swap on mine at some time and was hoping it was a 490 cylinder. Supposed to be a hot rod of a saw.

Yes, it's 45mm. ModifiedMark explained this to me on the phone. That number is Mahle's casting number, not an actual part number. Mahle casts these cylinders, then it's up to the manufacturer to decide the bore and port timing. All 490s 590s Partner 5000 closed port and Partner 5000+ will have that same number. I'm willing to bet my PP325 46mm will have the same number, providing the cylinder is Mahle. Bore and timing can be different from each.

Mark, feel free to add anything if I left it out.

 

[Arrowhead]

Nope
The 45 mm was all I need
trying to positive i.d. a j'red I have.
sticker on the case says 490, metal tag says 590.
Goodluck with the rebuild.

If the metal tag by the throttle says 590 and it's a 45mm bore, it's a 590. Is the case sticker on the clutch cover your speaking of?

 

[Modifiedmark]

Yes, it's 45mm. ModifiedMark explained this to me on the phone. That number is Mahle's casting number, not an actual part number. Mahle casts these cylinders, then it's up to the manufacturer to decide the bore and port timing. All 490s 590s Partner 5000 closed port and Partner 5000+ will have that same number. I'm willing to bet my PP325 46mm will have the same number, providing the cylinder is Mahle. Bore and timing can be different from each.

Mark, feel free to add anything if I left it out.

Well thats the way I see it till I'm proven something different anyway.

Just makes too much sense.

I'm always willing to learn though .

 

[Arrowhead]

Not surprising on the compression after looking at the picture of the combustion chamber, it looked pretty small.

Nice job and a interesting thread. I have never been that deep into one yet.

Yea, the small combustion chamber and huge windows in the piston help to make these saws screamers. :msp_w00t:

 

[Arrowhead]

All the Partner 5000+'s have a full circle windowed piston, unlike the 590 piston.

 

[wigglesworth]

Yes, it's 45mm. ModifiedMark explained this to me on the phone. That number is Mahle's casting number, not an actual part number. Mahle casts these cylinders, then it's up to the manufacturer to decide the bore and port timing. All 490s 590s Partner 5000 closed port and Partner 5000+ will have that same number. I'm willing to bet my PP325 46mm will have the same number, providing the cylinder is Mahle. Bore and timing can be different from each.

Mark, feel free to add anything if I left it out.

Im not Mark, but Id thought id share a bit. Yes, the 490, 590, 5k all share the same casting number on the jug, but so do the closed port 55 husky's. The without putting a degree wheel on them, the only visible differences are the bore size (490/5k is 44mm, 590/55 is 45mm) and combustion chamber volume, where the 44mm jugs have a real small chamber. And the 55 jugs have a decomp port. Also, as you already noted, the 44mm's have a full circle piston, and the 590/55's have the regular windowed 45mm piston. Im willing to make a wager that the 55/590 is the exact same part, at least they sure do look that way. I can measure a 55 closed port piston tomorrow, so Ed if you do take the jug back off, we can compare. I do know the casting number is the same for them.

 

[Arrowhead]

Im not Mark, but Id thought id share a bit. Yes, the 490, 590, 5k all share the same casting number on the jug, but so do the closed port 55 husky's. The without putting a degree wheel on them, the only visible differences are the bore size (490/5k is 44mm, 590/55 is 45mm) and combustion chamber volume, where the 44mm jugs have a real small chamber. And the 55 jugs have a decomp port. Also, as you already noted, the 44mm's have a full circle piston, and the 590/55's have the regular windowed 45mm piston. Im willing to make a wager that the 55/590 is the exact same part, at least they sure do look that way. I can measure a 55 closed port piston tomorrow, so Ed if you do take the jug back off, we can compare. I do know the casting number is the same for them.

I figured I'd let you or Mark let the cat out of the bag on the Husky 55 epa's. LOL Yes, that same number also. I may pull the jug, just so we can get some accurate measurements. I would like to cc the combustion chambers. If we both do accurate port maps, that should tell us if the timing is close. Sound good?

 

[mama]

I've got a couple 5000 partners, where did you get your new AV parts. Thanks.

 

[Arrowhead]

I've got a couple 5000 partners, where did you get your new AV parts. Thanks.

Any Poulan dealer will have them. They are the same as the Poulan Pro 325. I can send you an IPL. I can tell you who's cheapest through a PM. :msp_wink:

 

[SawTroll]

the saw I'm trying to i.d. is a 45 mm ,closed port.

45mm closed port, and a bit like the 930 in the porting.

 

[Arrowhead]

I wanted to let you guys know that a decal kit for the 490/590 will be available in about a week. Joe at Sugar Creek Supply emailed me yesterday and said they are almost finished. He does an incredible job, and great prices.

 

[dk27]

Is the case sticker on the clutch cover your speaking of

correct

 

[Arrowhead]

I'm needing a starter cover and air filter for a 490 I have. Anybody have any spares?

 

[wendell]

Amazing work as always, Ed. You definitely are a "rare breed"!

 

[Arrowhead]

LOL... Thanks Steve.

I'm going to try to get a video up tomorrow, if it's not raining.

 

[Chris J.]

Ed, great thread, thanks for including all the photos , I'm looking forward to the video.

 

[SawTroll]

The saw is complete. :msp_smile:

Minus the decales - LOL. :msp_biggrin:

 

[Arrowhead]

Minus the decales - LOL. :msp_biggrin:

I hope to have the new decals in a week or so.