Jonsered Chainsaws

[Cantdog]

Robin probably knows better as he has seen a lot of these saws, but I think it's an early vs. late thing.

Nope........It's a semi Pro VS. a Pro thing....LOL!! The 52 has the same tank vent and hose system as the 621, 80 etc. The 49 has a similar setup to more modern saws...IE; a single hose from the carb through an interference fit hole in the tank and down to the filter.....except the 49 also uses the same one way check valve (tank vent) as the Pro saws but it threads into the top of the tank instead of the plastic block of the 52/621 etc. The advantage of the 49 setup is a common sized fuel line utilized in a singe piece. The Pro setup uses a very special sized/formed hose from the fuel block to the carb....it has a different size end on the fuel block end...much larger dia......sounds like a PITA but in reality is a very functional setup (assuming you can get that special hose when needed)........the special upper hose lasts a very long time but the intank line fails much mote frequently...so rather than replacing the whole thing you were meant to just replace the intank (lower) fuel line as needed......didn't need to take the top covers etc. off for the fix...only remove the gas cap all work done through there. As most of you already know the intank line is held onto the hose barbs on the fuel block and the fuel filter with what at first appear to be very heavy duty crimp clamps......they are not....the ss collars are meant to be pried off the hose ends, the hose removed and the collars reinstalled on the new fuel line back away from the hose ends before installation...once the hose is on the barb the collar is pried back over the hose barbs on both ends...pretty damn slick rig if you know how it is supposed to work....most folk discarded the collars and then had a hard time keeping the upper end of the fuel line on the plastic barb once the line softened to the fuel mix.

Add to this the original Jonsereds fuel filter that you did not replace as a whole but took apart and cleaned the sintered bronze inner filter and bought a new felt outer filter for a buck and you rebuilt your fuel filter rather than buying a whole new filter......there was a plan...and a damn good one actually from a repairable in the field perspective......which is just another thing that always set Jonsereds apart from other less thought out saws.....

 

[Real1shepherd]

The top pic of the vent system is the only configuration I've seen in the 80's/90's that I have(and I would assume the same in the 801 as well).

So in the bottom pic, I assume the open hole was for the gas line and the vent is as shown(if so, I would expect a different fuel line, grommet-ed, like in the Husky 2100)? Where did the vent line terminate...same place as the earlier design? If that's the only difference in the cases, I sure wouldn't sweat it.

Robin is the reigning King on the 49SP.....he should be able to answer anything about it.

LOL...after I hit send I saw Robin's answer come in. NO,NO,NO.....Never throw those fuel line clips away, they are totally reusable! The fuel/vent box gaskets are pretty brittle at this point in time and are rubberized. I would assume they are gas rated as well.....can't find those anymore. I like the idea that they are somewhat elastic and therefore will seal easier than a rigid gasket.

Kevin

 

[Cantdog]

The top pic of the vent system is the only configuration I've seen in the 80's/90's that I have(and I would assume the same in the 801 as well).

So in the bottom pic, I assume the open hole was for the gas line and the vent is as shown(if so, I would expect a different fuel line, grommet-ed, like in the Husky 2100)? Where did the vent line terminate...same place as the earlier design? If that's the only difference in the cases, I sure wouldn't sweat it.

Robin is the reigning King on the 49SP.....he should be able to answer anything about it.

LOL...after I hit send I saw Robin's answer come in. NO,NO,NO.....Never throw those fuel line clips away, they are totally reusable! The fuel/vent box gaskets are pretty brittle at this point in time and are rubberized. I would assume they are gas rated as well.....can't find those anymore. I like the idea that they are somewhat elastic and therefore will seal easier than a rigid gasket.

Kevin

Yes the open hole was for the fuel line.......now...and this is important.....the vent line comes out of the valve...goes straight up and is formed over the choke shaft then down under the carb...across the air box to the right and exit through a hole into the clutch area with a sintered bronze filter in the end...

 

[Cantdog]

The top pic of the vent system is the only configuration I've seen in the 80's/90's that I have(and I would assume the same in the 801 as well).

So in the bottom pic, I assume the open hole was for the gas line and the vent is as shown(if so, I would expect a different fuel line, grommet-ed, like in the Husky 2100)? Where did the vent line terminate...same place as the earlier design? If that's the only difference in the cases, I sure wouldn't sweat it.

Robin is the reigning King on the 49SP.....he should be able to answer anything about it.

LOL...after I hit send I saw Robin's answer come in. NO,NO,NO.....Never throw those fuel line clips away, they are totally reusable! The fuel/vent box gaskets are pretty brittle at this point in time and are rubberized. I would assume they are gas rated as well.....can't find those anymore. I like the idea that they are somewhat elastic and therefore will seal easier than a rigid gasket.

Kevin

No on the 49 cases there is but a small hole fore the fuel line......on the Pro saws there is a ...like 3/4" hole that the plastic fuel block goes into....and four threaded holes....definite case change.....between the 52/52E and the 49sp.......the only one too, I believe....

 

[WoodDean]

The top pic of the vent system is the only configuration I've seen in the 80's/90's that I have(and I would assume the same in the 801 as well).

So in the bottom pic, I assume the open hole was for the gas line and the vent is as shown(if so, I would expect a different fuel line, grommet-ed, like in the Husky 2100)? Where did the vent line terminate...same place as the earlier design? If that's the only difference in the cases, I sure wouldn't sweat it.

Robin is the reigning King on the 49SP.....he should be able to answer anything about it.

LOL...after I hit send I saw Robin's answer come in. NO,NO,NO.....Never throw those fuel line clips away, they are totally reusable! The fuel/vent box gaskets are pretty brittle at this point in time and are rubberized. I would assume they are gas rated as well.....can't find those anymore. I like the idea that they are somewhat elastic and therefore will seal easier than a rigid gasket.

Kevin

So . . . . . I'm not the only one who just noticed!!! well that's cool.
And now that I've confirmed I have a 52 case, I think I'll take the 49 piston off it's connecting rod and build a 52 since I have a good p/c!!!!!

And thank you Robin for the explanation regarding the collars/clamps and how they function. Always good to read your posts.

 

[WoodDean]

took apart and cleaned the sintered bronze inner filter and bought a new felt outer filter for a buck

Yup, JUST took one of those apart last weekend and noticed the design. But I've never seen any of the new felts for sale. Maybe they're available through another company like Stens?

 

[Real1shepherd]

No on the 49 cases there is but a small hole fore the fuel line......on the Pro saws there is a ...like 3/4" hole that the plastic fuel block goes into....and four threaded holes....definite case change.....between the 52/52E and the 49sp.......the only one too, I believe....

Well I'm not sure on the 621 because I haven't worked on mine yet, but the 80/801/90 all have that gas/vent box configuration and I've never seen anything else on those saws...ergo, they are probably all that way as Pro saws. However, due to varied PO's, my Arkansas 90, was bone stock with the sintered bronze filter on the end of the vent line. I did post a source for those bronze vents on ebay. On all my saws, I've routed that vent line just as the factory did...AND from the factory there is supposed to be a wire clip off one of the top plate carb screws on the clutch side, that the vent is tucked through. I only have two saws where the PO's didn't lose that clip.

As I've said many time in here in the past, that Pro vent system isn't the best...it WILL vaporize your fuel if you park your hot saw in the sun. Park it in the shade no matter how hot the day is and you're good to go.

Love the fuel filter set-up on the old Pro J'red saws. I've never had to replace a felt yet....chem them clean if you have to until they completely fall apart. Their function is as a pre-filter for the sintered bronze filter. The Husky 2100 had an interesting fuel filter too, but most owners eventually tossed them and stuck on those generic white bastards. They work, but the OE filter was much better.

Kevin

 

[Real1shepherd]

Yes the open hole was for the fuel line.......now...and this is important.....the vent line comes out of the valve...goes straight up and is formed over the choke shaft then down under the carb...across the air box to the right and exit through a hole into the clutch area with a sintered bronze filter in the end...

So on the 49 with that fuel line coming through that small case hole....is the fuel line itself grommet-ed there, or thicker than the hole causing you to pull hard on the line? I think you said above "interference fit", so I take that to mean just tight, no grommet?

Kevin

 

[Cantdog]

Yup, JUST took one of those apart last weekend and noticed the design. But I've never seen any of the new felts for sale. Maybe they're available through another company like Stens?

Nope just a Jonsereds thing and like a lot of stuff NLA...

 

[Cantdog]

So on the 49 with that fuel line coming through that small case hole....is the fuel line itself grommet-ed there, or thicker than the hole causing you to pull hard on the line? I think you said above "interference fit", so I take that to mean just tight, no grommet?

Kevin

No grommet...just a standard fuel line...the 70E is the same way...

 

[Cantdog]

So . . . . . I'm not the only one who just noticed!!! well that's cool.
And now that I've confirmed I have a 52 case, I think I'll take the 49 piston off it's connecting rod and build a 52 since I have a good p/c!!!!!

And thank you Robin for the explanation regarding the collars/clamps and how they function. Always good to read your posts.

Yeah but.......now you have to find out if yours is a 52 or 52E..........

 

[Chris J.]

Dang, Robin, I was hoping that you'd post some detailed info .

...

And thank you Robin for the explanation regarding the collars/clamps and how they function. Always good to read your posts.

I second that thought!

 

[taplinhill]

Oh no! One of my 49sp's is a Hybrid Bastid! 49 top end with 52 bottom. I can't remember if that is one of my junk pile builds or not. I don't know how Robin can keep nine of them straight. I've got 6 runners, 3 complete parts saws and 4 carcasses and can't remember. I swear 49's breed.

 

[WoodDean]

Yeah but.......now you have to find out if yours is a 52 or 52E..........

Mindreader, I just logged in to post some questions about the differences.

I'm assuming that if I have just a stripped case, then I can build whichever model I prefer 52 or 52e, true?
If that's correct, I'd like to build a 52 which means I'll need to buy a points plate and this shares the powderhorn looking coil with the 111s.

Also, some flywheels don't have any fins on them . . . . although I have seen the flywheel fin rings but when or why they were installed I can't tell.
My guess is the 52e had the fins the 52 did not. Can you shed a little light on that???

 

[WoodDean]

Oh no! One of my 49sp's is a Hybrid Bastid! 49 top end with 52 bottom. I can't remember if that is one of my junk pile builds or not. I don't know how Robin can keep nine of them straight. I've got 6 runners, 3 complete parts saws and 4 carcasses and can't remember. I swear 49's breed.

Heh, reminds me of that Cher song from the 70's;

Half-breed, that's all I ever heard
Half-breed, how I learned to hate the word
Half-breed, she's no good they warned
Both sides were against me since the day I was born

 

[Cantdog]

Mindreader, I just logged in to post some questions about the differences.

I'm assuming that if I have just a stripped case, then I can build whichever model I prefer 52 or 52e, true?
If that's correct, I'd like to build a 52 which means I'll need to buy a points plate and this shares the powderhorn looking coil with the 111s.

Also, some flywheels don't have any fins on them . . . . although I have seen the flywheel fin rings but when or why they were installed I can't tell.
My guess is the 52e had the fins the 52 did not. Can you shed a little light on that???

Yes you can build either if starting from scratch but you will need the points plate, points and condenser as well as the magneto coil and the appropriate spark coil. The E is simpler to build as it all just bolts together whereas the points version will need to be timed and the points set.. But the E components are hard to come by and harder still to replace.....so at this juncture probably the points version will be less problematic in the long run.

There are two separate steel flywheels, 504 62 00 06 is for the "E" model (also fits the 70E) and 504 62 00 01 is for the standard points ign...the black plastic fans are the same for both flywheels....and both require the fans be installed....

 

[Real1shepherd]

I figured there would be flywheel differences between them. Given how hard electronic modules are to find for most of the older Jonsered, I'd sure go with the points plate and two coils.....seems to be a fair number of them floating around, like on the bay. It's nice to have electronic modules...until they fizz out. For example, I think the magneto coil for the 910E is in unobtainium status now, or at least when you see one it's $125+. The points set up in these older J'reds is about as bullet proof as they can be. Three pulls max on a cold day...1-2 on a warm day....if you're quick with the choke...lol.

After I retired my 80 from loggin', it went another 13yrs on the farm before I opened up the points compartment. I'd say that's durable. But then again, the original silver tops are unstoppable with routine maintenance.

Kevin

 

[WoodDean]

...the black plastic fans are the same for both flywheels....and both require the fans be installed....

Black plastic? Never saw any of those. I usually see this type, the metal kind;

 

[Cantdog]

Black plastic? Never saw any of those. I usually see this type, the metal kind;

View attachment 485310

The 52/52E had plastic fans part # 504 61 25 01 The 50 and 51 had a different part number or their fans #504 61 25 04 I assumed these to be plastic as well but do not have any of those saws......so perhaps these were metal...the steel flywheels themselves are the same for the 50, 51 and 52......Eric may know more on this issue....

 

[taplinhill]

My 50, 51, 52 and 52E all have plastic flywheel fins.