Jonsered Chainsaws

[Cantdog]

Wow...that would be easier! There are two style screens apparently;one is round and bulbous like you pictured and one housing has a flatter screen/assembly. I always assumed the 90 used the bulbous screen and the 80 used the flatter screen. But I think I'm wrong on that measure, because this 90 has a flat screen and I think it's OE.

But hell yeah, I'll buy your screen/housing because I like the bulbous screen to be on the 90's.

Kevin

My IPLs show the 801 and 90 could have come either/both ways.....the 80 shows only the flat type....the rounded type of screen (part # 504 36 35 05) is also used on the 70E as well.....

Good score on that screen.....it's in pretty darn good shape....little straightening be as good as new!! I think the rounded type is easier to damage than the flat ones......

 

[Real1shepherd]

My IPLs show the 801 and 90 could have come either/both ways.....the 80 shows only the flat type....the rounded type of screen (part # 504 36 35 05) is also used on the 70E as well.....

Good score on that screen.....it's in pretty darn good shape....little straightening be as good as new!! I think the rounded type is easier to damage than the flat ones......

Yeah, they are be easier to dent....but the bulbous one just looks 'right' on the 90, to me. I thought I saw an 80 on ebay with a bulbous cover....but it may have been a replacement. And yeah, I have seen some 70E's for sale with the bulbous cover....so apparently, there's no engineering advantage one way or the other. I haven't really noticed if one style get dirtier than the other in actual use. You'd think there would be more airflow in the bulbous screen, but maybe more 'directed' flow in the flat screen-less surface area. Maybe it was J'red saving some money and going with the flat screen and/or complaints about smashing the bulbous screen.

Kevin

 

[WoodDean]

Wow...that would be easier! There are two style screens apparently;one is round and bulbous like you pictured and one housing has a flatter screen/assembly. I always assumed the 90 used the bulbous screen and the 80 used the flatter screen. But I think I'm wrong on that measure, because this 90 has a flat screen and I think it's OE.

But hell yeah, I'll buy your screen/housing because I like the bulbous screen to be on the 90's.

Kevin

FYI - The only good thing about my housing is the screen. The housing has a couple tabs broke off where the Allen screws secure it to the case. Which is why I had to buy a new one. Not sure how a rounded screen would fit on a flat housing? Still, if you want it, it yours. PM me your address and I'll mail it out.

 

[Real1shepherd]

FYI - The only good thing about my housing is the screen. The housing has a couple tabs broke off where the Allen screws secure it to the case. Which is why I had to buy a new one. Not sure how a rounded screen would fit on a flat housing? Still, if you want it, it yours. PM me your address and I'll mail it out.

No, won't work then...round to round and flat to flat. If I had an extra round housing with a bad screen, your offer would be perfect. Thanks though!

All the surplus housings I have are for flat screens...other than the round one on my runnin' 90.

Kevin

 

[Real1shepherd]

As an aside, I re-timed the 90. I found my dial indicator, but couldn't find the spark plug hole adapt. So I have a TDC tool that has a rod that protrudes as you reach TDC. In the J'red service manual, they say to put a piece of .05mm paper in the points and then rotate the shaft counterclockwise until the points just releases the paper-that's when the magneto first fires. Then you keep rotating until you're at TDC and then measure the difference. Well, that sounds great on paper but the 'moment' the points release the paper is debatable...i.e., when there still is some drag or completely free etc?? It will affect your measurements wildly. Eventually after a lot of finger fudging around, I think I got close to their magic 2.7mm number. Don't know how critical this really is, but I think their method to find timing is weird.

Kevin

 

[WoodDean]

As an aside, I re-timed the 90. I found my dial indicator, but couldn't find the spark plug hole adapt. So I have a TDC tool that has a rod that protrudes as you reach TDC. In the J'red service manual, they say to put a piece of .05mm paper in the points and then rotate the shaft counterclockwise until the points just releases the paper-that's when the magneto first fires. Then you keep rotating until you're at TDC and then measure the difference. Well, that sounds great on paper but the 'moment' the points release the paper is debatable...i.e., when there still is some drag or completely free etc?? It will affect your measurements wildly. Eventually after a lot of finger fudging around, I think I got close to their magic 2.7mm number. Don't know how critical this really is, but I think their method to find timing is weird.

Kevin

I was just about to ask how this was done. I think I need to get a service manual. Obviously I wasn't the first one to take the plate off by the looks of the rounded off allen screws. Now I'm wondering if the timing was correct. And I discovered this, may or may not affect performance but a dented condenser could be a problem;

 

[WoodDean]

oh, and how do you generally get this thing off? I see it's keyed so I guess my only option is a gear puller ?????

 

[WoodDean]

Ready for those new seals!

 

[Real1shepherd]

I was just about to ask how this was done. I think I need to get a service manual. Obviously I wasn't the first one to take the plate off by the looks of the rounded off allen screws. Now I'm wondering if the timing was correct. And I discovered this, may or may not affect performance but a dented condenser could be a problem;

View attachment 342084

I don't know how much a condenser can take dent-wise...but that's gotta be over the top. I get really suspicious when I get inside a points assembly and see things butchered like that, huge gouge pry marks on the flywheel etc. You've got small, almost delicate fasteners under the flywheel and you should at least be using metric ignition wrenches etc. This is a place where you want to take your time and not rush things.

I can send you the service manual procedure...I already transferred it to pdf. Read that and then read how I did it above and you should be in gravy.

Kevin

 

[WoodDean]

Th

I don't know how much a condenser can take dent-wise...but that's gotta be over the top. I get really suspicious when I get inside a points assembly and see things butchered like that, huge gouge pry marks on the flywheel etc. You've got small, almost delicate fasteners under the flywheel and you should at least be using metric ignition wrenches etc. This is a place where you want to take your time and not rush things.

I can send you the service manual procedure...I already transferred it to pdf. Read that and then read how I did it above and you should be in gravy.

Kevin

Thanks for the manual Kevin, much appreciated. I'll PM you an address. I ordered a new condenser from Sawagain.

 

[Real1shepherd]

Sent.

Kevin

 

[fossil]

I finally got my 801 going. The PO was retaining compound crazy which meant the inner bearing race was stuck on the crank, the flywheel was stuck on and I hit the trigger coil with a puller bolt. I had to finally use a fait bit of heat to get it off. The key in the clutch hub was cocked and I couldn't get it free with a pic so I had to drill it out and make a new one.
The oiler line was off inside the tank so I put a new one in with a mirror and a pair of angled locking dentist's tweezers.
I installed new crank seals, a carb kit and fuel filter and repaired the broken wires on the coil.
It pulls pretty hard. I am pleased with the way it turned out but it was a bit frustrating to work on due to that compound.
My first Jonsereds and a good old machine it is. I would buy another in a heartbeat. They seem to be scarce around me even though they seemed to be the saw of choice in northern logging country.
Here's a quick poor quality vid of a cut in small wood. I tred to make some in larger wood but my little camera is acting up.
Thanks to Realshperd1 for the clutch spring and all the help.
http://s731.photobucket.com/user/Fossil1/media/cuts/Jonsereds8013-31-14_zpsb6cc28bc.mp4.html

 

[Real1shepherd]

Yeah....she's baaaad now, Tim! Sounds good for that little bar.

We should compile a book; The Dumb Things People Do To Chainsaws.......or, Miscreants and Chainsaws.....

Kevin

 

[SawTroll]

Yeah, they are be easier to dent....but the bulbous one just looks 'right' on the 90, to me. I thought I saw an 80 on ebay with a bulbous cover....but it may have been a replacement. And yeah, I have seen some 70E's for sale with the bulbous cover....so apparently, there's no engineering advantage one way or the other. I haven't really noticed if one style get dirtier than the other in actual use. You'd think there would be more airflow in the bulbous screen, but maybe more 'directed' flow in the flat screen-less surface area. Maybe it was J'red saving some money and going with the flat screen and/or complaints about smashing the bulbous screen.

Kevin

The 66E had the bulbous screen as well as the 70E of course (I have one).

Regarding the 90 and 801, I think it is reasonable to assume that it was the early ones that inherited the "flat" screen from the 80.

 

[fossil]

Yeah....she's baaaad now, Tim! Sounds good for that little bar.

We should compile a book; The Dumb Things People Do To Chainsaws.......or, Miscreants and Chainsaws.....

Kevin

Heck, no Kevin. That would have to be a ten volume set.

 

[Cantdog]

As an aside, I re-timed the 90. I found my dial indicator, but couldn't find the spark plug hole adapt. So I have a TDC tool that has a rod that protrudes as you reach TDC. In the J'red service manual, they say to put a piece of .05mm paper in the points and then rotate the shaft counterclockwise until the points just releases the paper-that's when the magneto first fires. Then you keep rotating until you're at TDC and then measure the difference. Well, that sounds great on paper but the 'moment' the points release the paper is debatable...i.e., when there still is some drag or completely free etc?? It will affect your measurements wildly. Eventually after a lot of finger fudging around, I think I got close to their magic 2.7mm number. Don't know how critical this really is, but I think their method to find timing is weird.

Kevin

Yeah the paper thing can be a little arbitrary........here is a way that will tell you the exact moment the points open. This is how I time my 1959 Harley Panhead.......on the bike you simply turn the switchkey on....on a saw you will have to use a separate power supply, like a small trickle charge or battery so you have power running through the points which then lights a test light.....on the Harley the left twist grip operates the spark advance...rotated all the way towards the driver/rear is full advance....rotated all the way forward/away from the drive is fully retarded. Timing is adjusted at full advance....with the timing marks on the flywheels set at a specific spot (35 degrees advance)....the instant you start to manually retard the timing the points should open which in turn shuts the light off. Same can be done on a saw....of course crank position is all important. I have a spark plug adapter and dial indicator I can lend you...or just the adapter to use with your indicator, just shoot me a PM with your addy...the test light will tell you the instant the points open but I am not sure how that will relate to having a half mm piece of paper already holding the points open that much........all I do know for certain if you are to far advanced....that 80 will treat your fingers just like that 74cid Harley will treat your leg....LOL!!

 

[Real1shepherd]

Yeah the paper thing can be a little arbitrary........here is a way that will tell you the exact moment the points open. This is how I time my 1959 Harley Panhead.......on the bike you simply turn the switchkey on....on a saw you will have to use a separate power supply, like a small trickle charge or battery so you have power running through the points which then lights a test light.....on the Harley the left twist grip operates the spark advance...rotated all the way towards the driver/rear is full advance....rotated all the way forward/away from the drive is fully retarded. Timing is adjusted at full advance....with the timing marks on the flywheels set at a specific spot (35 degrees advance)....the instant you start to manually retard the timing the points should open which in turn shuts the light off. Same can be done on a saw....of course crank position is all important. I have a spark plug adapter and dial indicator I can lend you...or just the adapter to use with your indicator, just shoot me a PM with your addy...the test light will tell you the instant the points open but I am not sure how that will relate to having a half mm piece of paper already holding the points open that much........all I do know for certain if you are to far advanced....that 80 will treat your fingers just like that 74cid Harley will treat your leg....LOL!!

I like the idea of using the light....maybe just without that piece of .05mm paper(printer paper is too thick, but the paper that bill collectors send is just perfect....lol!) If only J'red had seen fit to put some timing marks somewhere. Nah, don't worry about the dial indicator spark hole adpt(but thanks)...measuring the protrusion of the TDC tool was plenty accurate...just a bit twitchy compared to a dial indicator. My main thing now is to find out where the compression is going and finding time to get back into the saw!

Kevin

 

[Real1shepherd]

Heck, no Kevin. That would have to be a ten volume set.

Lol...I hadn't considered that, Tim...Volumes I-X.

Kevin

 

[Real1shepherd]

The 66E had the bulbous screen as well as the 70E of course (I have one).

Regarding the 90 and 801, I think it is reasonable to assume that it was the early ones that inherited the "flat" screen from the 80.

I sure wouldn't assume anything in this case. It's just as logical to 'assume' that J'red cut expenses on the 90 by going with the flat screen on later production saws. If I was on a fact finding mission from Hell, I'd be inclined to cross serial #'s and see what the flat versus bulbous screen is about. I've never paid any attention to if I have 'early' 90's/80's or 'late' etc. I think the plate off the work 80 is long gone, anyway.

About five yrs ago, I did find something strange on the work 80. There was some bar oil seeping out of the saw in a strange place. Just below the muffler, at the top of the oil tank was a very small Cotter pin head just visible. For the life of me, I can't imagine anyone putting that there...or more importantly, why would J'red?? On the ebay 90 I'm working on....I see the same tiny head of a Cotter pin poking through....so yeah, what's that all about? I wouldn't have even seen it if there wasn't a wee oil leak in the old 80.....it's that small.

Kevin

 

[shawn022]

Hey Kevin, that's the oil tank vent. They kept things pretty simple back then, didn't they?