Jonsered Chainsaws

[taplinhill]

The saw is a fairly late production 621.

And it even has the spark plug cover on it! Those are hard to come by.

 

[bigbadbob]

Well back to the shop,, gave the 621 another shot down the throat,, she pops and runs like a top!! Checked the comp 200psi warmThat spark plug cover fits very snug.

Also dragged out a 510 (150 comp) and 49SP (135 comp) that I have had sitting for 18 months, one has a bad on/off switch and the other a bad plug.
Not a bad day 3 Jreds back to life!!! Miller time yet!!

 

[briantutt]

Not a bad day 3 Jreds back to life!!! Miller time yet!!

:smoking:

 

[SawTroll]

And it even has the spark plug cover on it! Those are hard to come by.

:jawdrop: Right, I don't think I ever have seen one of those before, except in broshures etc!

 

[taplinhill]

:jawdrop: Right, I don't think I ever have seen one of those before, except in broshures etc!

This is the nicest of my 621's and the only one with the plug cover.

 

[Cantdog]

Yep...Absolutely a 621....no doubt what-so-ever. The chain brake was an option...for a number of yrs...some also came with an ignition cut out so when activated it would also kill the engine, but not all. (OOPS on the reread I see Mark has already addressed this!! Sorry)

The 621s and 80 had very high domed pistons with two rings and are capable of rather high comp figures, so don't think it's a carbon buildup or some other detremental problem. These were designed to run on real leaded gasoline and could very well handle the comp.

The spark plug cover is a definite plus, you don't see many...I actually have a couple extras I've aquired along the way. The 621 is a Good saw by any timeline.

Nice 621 Eric!! One of mine is about that nice, the others have more normal wear and missing paint, etc. but are in excellent health and work well.

 

[8433jeff]

This is the nicest of my 621's and the only one with the plug cover.

Yes, thats a nice saw. Love the perforated beer can filter lol. Which are hard to come by, in my experience.

 

[SawGarage]

HHMMM!!
Did the 621 come with a chain brake?? This one has one, a piece that pushes against the clutch drum.
Bob

Looks to me like a late model 621 with the chain brake. I think you will find the brake operates a small shoe against the clutch drum, and a stop switch that kills the engine when activated.

Mark

That's exactly how the brake on my 70E is "supposed" to work...

ON the topic of the chainbrakes.... I have at least 2 of retrofit 'kits' for the 621 with the shoe, and ign lead from a dealer that closed saw business where a buddy worked... anyone know anything bout this??

And it even has the spark plug cover on it! Those are hard to come by.

This is the nicest of my 621's and the only one with the plug cover.

Nice Eric!! I know most of your saws are REALLY ROUGH looking :spam:

would the plug cover be silver? or painted plastic?

I know I have quite a few of the black ones.

I've been blessed that BOTH my 801, and 70 BOTH came with the plug covers...and bought them complete for 'parts saw' prices

The 621s and 80 had very high domed pistons with two rings and are capable of rather high comp figures, so don't think it's a carbon buildup or some other detremental problem. These were designed to run on real leaded gasoline and could very well handle the comp.

I will attest to the 801. the dome was SO HIGH I could barely measure the bore!!

 

[heimannm]

The spark plug cover is molded from a silver plastic.

Mark

 

[bigbadbob]

My Jred 90 as I bought it. Runs excellent.
May have posted before,, but what the heck nice saw!!!

 

[SawGarage]

Bob...

very nice!!!

love the "full" wrap handle...

J

 

[bigbadbob]

Bob...

very nice!!!

love the "full" wrap handle...

J

Thanks it was an interesting thing getting the saw to run well, the original
fuel filter (the brass bead type) had a small hole in it,, plugged the main jet some. The saw was a dog, and probably that way from shortly after new. Probably got set in a corner because it was a dog. Sure runs good now.
I posted a carb rebuild thread somewhere.
Came form a storage container sale with a 70 parts saw.

 

[SawTroll]

This is the nicest of my 621's and the only one with the plug cover.
.....

Really nice!

That also is a late one, even though it doesn't have the chain brake.

 

[tmessenger]

49sp ?

Picked up a 49sp today (low compression) saw looks to be not heavily used, what's the good news on pistons and rings for these. Haven't taken it down yet to see how bad it is so don't know if it's a fixer or if I'm going to part it out.

Tim

 

[Cantdog]

Picked up a 49sp today (low compression) saw looks to be not heavily used, what's the good news on pistons and rings for these. Haven't taken it down yet to see how bad it is so don't know if it's a fixer or if I'm going to part it out.

Tim

No good news for pistons..........NLA for a long time now..........and no aftermarket support either. Rings on the otherhand, are available. 44MM X 1.5MM. So as long as your piston isn't scored or worn completely out you should able to get it going for a few bucks. If you do have a toasted piston....good luck....they do show up on ebay NOS but extremely rare. Used more often but spendy. There is a used P&C on ebay now $70.00 plus shipping.......quite a bit for a saw that you can buy in good running condition for $100.00 IMHO.........If you get to discouraged..PM me....these are my favorite little Jonsereds...I can make it feel right at home.

The only other piston you could use would be from a 51, 52/52E but again NLA and no aftermarket, and these are not quite the same but will work.

Don't mean to be all doom and gloom but this is an issue that plagues these real nice saws.

 

[tmessenger]

Thanks Robin

I'll have a look at the p/c today and see if it will clean up, it's a neat little saw so wouldn't mind getting it going but yeah I'm not paying $80+ to make it happen.

No good news for pistons..........NLA for a long time now..........and no aftermarket support either. Rings on the otherhand, are available. 44MM X 1.5MM. So as long as your piston isn't scored or worn completely out you should able to get it going for a few bucks. If you do have a toasted piston....good luck....they do show up on ebay NOS but extremely rare. Used more often but spendy. There is a used P&C on ebay now $70.00 plus shipping.......quite a bit for a saw that you can buy in good running condition for $100.00 IMHO.........If you get to discouraged..PM me....these are my favorite little Jonsereds...I can make it feel right at home.

The only other piston you could use would be from a 51, 52/52E but again NLA and no aftermarket, and these are not quite the same but will work.

Don't mean to be all doom and gloom but this is an issue that plagues these real nice saws.

 

[tmessenger]

I pulled the 49sp down today the piston was not real bad and the cylinder is good so a little clean up and a ring should bring it around. I'd like to replace the cranks seals while I have it apart are these a dealer only item or is after market available, anyone have the # for the seals ?

Thanks

Tim

 

[Cantdog]

How did the piston measure?? It's probably good but I've had pistons that looked great but in reality were worn out (0.012"-0,016" undersize) The realistic wear limit is about 0.006 under. You said it looked to have low hrs so it's probably fine. But you should check. Make sure you clean out any carbon from the ring groove and lands before you reassemble.

 

[Cantdog]

Oh.. the seals are 35MM X15MM X 7MM double lipped. Can be had at any good industrial bearing store.

 

[SawGarage]

No good news for pistons..........NLA for a long time now..........and no aftermarket support either. Rings on the otherhand, are available. 44MM X 1.5MM. So as long as your piston isn't scored or worn completely out you should able to get it going for a few bucks. If you do have a toasted piston....good luck....they do show up on ebay NOS but extremely rare. Used more often but spendy. There is a used P&C on ebay now $70.00 plus shipping.......quite a bit for a saw that you can buy in good running condition for $100.00 IMHO.........If you get to discouraged..PM me....these are my favorite little Jonsereds...I can make it feel right at home.

The only other piston you could use would be from a 51, 52/52E but again NLA and no aftermarket, and these are not quite the same but will work.

Don't mean to be all doom and gloom but this is an issue that plagues these real nice saws.

I seem to have a couple NOS 44mm pistons with quite a crown...hmm :monkey:

How did the piston measure?? It's probably good but I've had pistons that looked great but in reality were worn out (0.012"-0,016" undersize) The realistic wear limit is about 0.006 under. You said it looked to have low hrs so it's probably fine. But you should check. Make sure you clean out any carbon from the ring groove and lands before you reassemble.

+1 :agree: once the machine marks are gone, it's pretty much time to replace...UNLESS it's NLA...

J