Chainsaw restoration questions (Jonsered 451 EV)

[DennisCA]

Hello all!

I just bought an old chainsaw, Jonsered 451 EV (supposed to be in running order but I will have to see) and I plan to renovate it and actually use it too. I just like older tech that can be more readily serviced at home than buying new stuff, and all the plastic on modern saws too. I like Jonsereds, my granddad had those and I remember using a small one as a kid to help with the firewood, remember I was bloody scared of it!





But there are already some questions I have, mainly it's refinishing related. The covers on this saw are all aluminum and I was planning to repaint them, but what kind of paint do you guys recommend for this? 2K or 1K? A mix of paint and clear coat? I have used 2k epoxy before when I worked on a milling machine, but epoxy ages badly and is not shock tolerant so I don't think it's viable here except as a primer coat. 1K paint would be simple to get but not that durable, what did Jonsered use from factory I wonder?

Since most of this saw is aluminum, I don't think it's safe to use paint strippers, at least not the ones I use (lye!), are there even aluminum safe paint strippers?

Probably have more questions later but gotta go get the kids ready for school.

 

[DennisCA]

Been taking this apart, here's the the cylinder and piston coming apart. What do the experts say?

 

[Cantdog]

Looks pretty good to me.......cyl will clean up good....piston looks salvageable. I'd invest in a new ring. I would suggest, in the future when tearing down a saw, that you clean it as good as you can before taking it apart.

 

[DennisCA]

I figure it didn't matter since I plan to take it further and clean every part separarely before reassembly.

I am gonna run this saw on alkylate fuel hereafter and to be safe I wanted to tear it down and clean everything from old debris and carbon deposits.

I got an ultrasonic cleaner and will be putting a lot of the parts in that, but maybe not the cylinder since it's aluminum. Not sure if it will damage it or not, but don't want to risk it.

 

[Blackbruin]

Your safe in the ultrasonic with the cylinder.

 

[ChillyB]

Some chemicals made specifically for ultrasonic tanks are caustic and therefore not safe with aluminum. We use it at work. I put on a label warning about aluminum.

 

[DennisCA]

citric acid is something I use often, but not with aluminum... For this it will be dish soap and water I think. Probably some soaking in kerosene or mineral spirits for the cylinder.

 

[DennisCA]

An interesting tidbit, or so I thought, was that the clutch on this saw does not unscrew, it's attached on a taper exactly like the flywheel is.
I didn't notice first until removing the bushing then Isaw the slit for a key and understood. In that it seems different from more modern saws, based on what I've read anyway. Might be wrong?

Flywheel side, good to have a decent brass punch sometimes.

(note I put the nut back on before tapping it out)

 

[DennisCA]

As for repainting, going this far in taking it apart, Ifeel like it's worthwhile, on the other hand, I want to start using it too. Repainting will probably have to be 2k affair to be worth it and I don't like messing with isocyanates until I got myself a fresh air system.

 

[Cantdog]

That clutch is similar to all the old true Jonsereds, though the rest have three shoes and three holes to screw into to pull the spyder off whereas yours has but two. A word of caution....the 451 had a number iterations sporting different ign systems among other things so be certain before you buy parts as not all are the same.

 

[DennisCA]

Right I tapped it out using the same method as on the flywheel, taper looks identical.

Gonna look for a replacement ring, don't think there are OEM spares anymore so I'll have to take some accurate measurements of the cylinder and piston. And iirc rings need to be a certain material to work well with nicasil.

 

[DennisCA]

I am gonna be splitting the case later, I don't have a splitting tool but have read good things about using a heat gun and tapping it out.

No new gaskets available for these ones, but I understand the existing one can be reused (with some permatex or similar) if I can get it of whole.

If not, what is the best material? I have searched the forums on this, but I found myself getting more confused, apparently gaskets can be metal now too? Is that better than paper or cork?

I was originally thinking of using paper and also smearing a thin layer of permatex on it if I needed a new gasket.

 

[Cantdog]

Is there a reason you think the cases need splitting?

 

[DennisCA]

Well to better be able to clean the interior parts of gunk and deposits, I might not be able to get at everything like this. As well as for the learning experience. I could stop here and just try and flush out the crank case though and save the splitting for another time and saw.

 

[Cantdog]

Yep, I understand...... it seems like the right thing to do. However unless you need new main bearings, have to replace the crankshaft or have a leaking case gasket it's a lot of effort and potential grief that is unnecessary. You will never be able to save the case gasket even to use as template to cut a new one, let alone reuse. It is quite thin and will be stuck to the case faces. Will need to be scraped off in pieces.
When I clean up a lower end I pull the seals, fill the crank area with mix until it runs out and then rotate the crank while working an acid brush in every place you can reach. Repeat this process until the mix come out pretty much as clean as it went in. You can also clean the outside of the bearings and races with the acid brush. This is where the most crap will have settled out over the years.

 

[heimannm]

Robin is supplying very good information based on a lot of experience Dennis, you should take heed.

Mark

 

[DennisCA]

Can the seals be pulled without damaging them? Or are seals a standardized part so I should be able to get new ones based on dimensions rather than hunting for old OEM parts?

I stuffed a rag around the piston last night and went to town on the case with kerosene and a toothbrush and then compressed air, looks a bit better now but holy moly it's got a lot of grown in dirt... Felt like what it needs is to be completely soaked in a tub of kerosene.

I filled up the inside with kerosene too and left it overnight. Will be flushing it a couple of times like this at least.

I ran some parts through the ultrasonic cleaner, turns out the red paint got faded from that despite using water & dishsoap. Feeling renewed vigor in wanting to repaint it.

Also looking into recreating the original decals.

 

[DennisCA]

I tried to replicate the Jonsereds logo from photos

edit, also made a round logo. An approximation of the real deal, only measurement I know is the OD which is 2½" or 63.5mm. I should work a little on the jonsered logo, it's close to the old one, mainly the lower right part of the d needs to be rounded and not squared.

 

[Cantdog]

Can the seals be pulled without damaging them? Or are seals a standardized part so I should be able to get new ones based on dimensions rather than hunting for old OEM parts?

I stuffed a rag around the piston last night and went to town on the case with kerosene and a toothbrush and then compressed air, looks a bit better now but holy moly it's got a lot of grown in dirt... Felt like what it needs is to be completely soaked in a tub of kerosene.

I filled up the inside with kerosene too and left it overnight. Will be flushing it a couple of times like this at least.

I ran some parts through the ultrasonic cleaner, turns out the red paint got faded from that despite using water & dishsoap. Feeling renewed vigor in wanting to repaint it.

Also looking into recreating the original decals.

No, the seals will be damaged beyond reclamation on removal. Besides they are nearly 40 yer old rubber parts so should be replaced anyway. They are more or less standardized so you should measure accurately the ID, OD, and thickness and source from a bearing/seal house. Sorry I don't know off the top of my head what they cross to......as I said earlier the 451/451EV is somewhat of an odd ball Jonsereds with several different production runs with totally different parts so it will be necessary to verify the actual parts you need. This is rather inconsistent with the other Jonsereds series of saws which used many of the same parts through totally different saws, sizes and models.

Good work on the clean up but pop the seals out as I said earlier as most of built up debris will have settled between the outside of the bearings and the inside of the seal.

You can eliminate most of the faded/oxidization of the color by hand buffing with a buffing compound made for paint followed by a light coat of automotive wax.

 

[DennisCA]

Good to know, thanks. I did try and buff the parts (scratch-x meguiars usually works) but didn't seem to want to work this time. Maybe wax will help.