Rebuilding the Jred 590

[bama]

Can you blow through the tube? If you can blow through it, it should be open enough. I think that is just the end point for the tank vent. There are a couple of variations on that saw and those hoses.

 

[Danger Dan]

I wasn't really sure what you meantD Dan, so I snapped some more shots of everything.

The piston on the left is from a Husky 50 Rancher, (non window type). The one on the right is a 490 piston, (windowed full circle). As far as the muffler goes, the outlet hole is the one that counts. Some guys trash the baffle and others add holes to it. Keep the bolt bushings if you trash it. A general rule of thumb is the outlet hole area should be 85% of the inside exhaust port area, (not the flange outlet area). :smoking:

 

[Rowan]

Dan,

I did some crude measurements tonight using the 590 jug, stock it appears to be 64%, so it won't need much more.

I've learned a lot in the last few days...

I know understand closed and open transfer ports. Your pic is a great example.

When I started i had the intake and exhaust ports confused with transfers..... LOL. I realize I have tons more to learn.

I believe I've got a problem.... Chainsaw addiction is setting in.

 

[Rowan]

Went to check out the local guys spare parts today

I went by the local Jreds shop today.

Below are the parts he had stripped from old saws... He also had a new clutch and 7 and 8 tooth sprokets..... (I took the clutch and a few other items).

If anyone needs anything from the photo's let me know, he sound like he'll be reasonable with the pricing. He said he's going to pack up shop 4 years from now, I told him to put a list of parts together for me. He showed me 4 boxes of new parts that you can't get from Jred anymore, said they are from various discontinued saws. When I get the list I'll let you guys know what he's got... he mentioned 621/521, 2051, 2054......

Sorry no oiler assembly, he thought he had a new one, but when he looked in the box it wasn't there..... (pretty messy box though, so who know once he has a chance to itemize everything it may turn up.

 

[Mange]

If I remember correct the Jonny 590 and Partner 5500 is the the same.
I am not sure about this till I look over the files, but I think the crank's are not the same on 490 and 590.

I will have a look at them at a later date.. Don't know were I put the 590....

 

[SawTroll]

If I remember correct the Jonny 590 and Partner 5500 is the the same.
I am not sure about this till I look over the files, but I think the crank's are not the same on 490 and 590.

I will have a look at them at a later date.. Don't know were I put the 590....

Isn't the 5500 53.2cc, like the later 540??

 

[Rowan]

Should I be worried about the seals drying out?

Just curious....

The new top end should be here in a couple of days, it was shipped Monday. I've had this saw apart for a while now.....I've decided that I'm going to send the saw out to be woods ported (stupid site created a monster now I keep finding ways to spend more money on this thing.......)

Should I be worried about things drying out? Do I need to put some 2-stroke oil in the case and turn the crank over a few times? Or should it be fine the way it is?

 

[huskydave]

No but it is always a good idea to wrap a clean rag around the connecting rod to prevent dirt from getting into the cranckcase.

 

[Rowan]

New top end arrived today

My top end arrived by mail today from George Blake (thank you!!).

From my perspective (very limited knowledge base) it looks to be in good shape.

I thought it was odd how much difference there is in the 590/490 piston.... Shouldn't they be the same, just slightly smaller?

 

[Rowan]

How do I clean out the carbon build up on the Head?

I decided that instead of sending out the 490 top end to be woodsported prior to reassembly I will put it together and run it. I'll do some timed cuts using same chain/bar with and without a muffler mod. Then have it ported.

Also, my saw budget is small at the moment, and I'm still hunting for a 70 - 80cc project saw (looking for a diamond in the rough.....).

The questions:monkey: .......

1. What should I use to get the carbon build-up off the top of the 490 head (assuming its best to do so)?

2. The cylinder looks to be in great shape, no scratches that I can feel..... I can see a few minor ones..... Can I just re-ring and go or should I try to find someone to do a light hone for me?

Thanks in advance for your advice

 

[Danger Dan]

Hey Rowan, How's the 590 coming along? Did you get it running? :smoking:
Dan