Jonsered Chainsaws

[Real1shepherd]

The coil reads the magnet as it revolves around in a circle....so the position of magnet on the flywheel itself is important for timing....that it hasn't shifted and the position of the coil pickup itself has the correct gap relative to the flywheel. The lamination are the flat pieces of metal bonded to make the shape of the coil along with the copper wire wrap in the middle.

So compare the coil pickup gap on a running saw to this XF and locate the magnet position on the flywheel in relation to a fixed point on the flywheel......like the key way. They should be identical on both saws.

This is only relevant if the timing is off....I'd do the carb swap first, because this involves pulling flywheels to check magnet positions.

Kevin

 

[fossil]

Ok can someone explain to me what the coil laminations are? Thanks

Correctly called the armature. Pic here show one with two legs yours very likely has three. I usually use some part of that as a reference point to see if the flywheel has slipped. It easily happens when people use oil on the taper of the crank.

 

[Real1shepherd]

Scott, looks like most of the flywheel magnets in these ported J'red's are glued into tightly milled recesses inside the flywheel. Really no place to slip around like in larger small engines.....they could get loose from losing their bond, but that's about it. I would suspect the XF is the same? I guess I've never had a magnet issue per say, on a saw yet...seen plenty of issues on larger small engines though....lol.

Like Tim said, make sure someone didn't get oil on the flywheel shaft and cause the flywheel to slip from its factory position. Be sure to try a ferrous piece of metal against the flywheel where the coil would pick up....there should be a good amount of pull on your metal piece.

Try a different carb yet?

Kevin

 

[bulletpruf]

Scott, looks like most of the flywheel magnets in these ported J'red's are glued into tightly milled recesses inside the flywheel. Really no place to slip around like in larger small engines.....they could get loose from losing their bond, but that's about it. I would suspect the XF is the same? I guess I've never had a magnet issue per say, on a saw yet...seen plenty of issues on larger small engines though....lol.

Like Tim said, make sure someone didn't get oil on the flywheel shaft and cause the flywheel to slip from its factory position. Be sure to try a ferrous piece of metal against the flywheel where the coil would pick up....there should be a good amount of pull on your metal piece.

Try a different carb yet?

Kevin

Scott, I’m only good with Tilly’s and recently I even put the sandwich order on the bottom gasket assembly wrong so I’m not infallible.

Given that you have too much gas with a nice fat spark and given your timing is OK, it would indicate a carb issue. What kinda carb is in the XF? Are you sure the gas inlet needle is seating and level fork is adjust correctly for that carb?

Kevin

Sure sounds like carb to me.....but yeah, if you have a running XF with the same carb, swap 'em for a test. I'll see if I can find an IPL of that Tilly.

Kevin

I'd make this my Bible;
https://tillotson.ie/wp-content/uploads/2015/07/techinfo_hl_us.pdf

Did you take that Welsh plug out and check the idle discharge ports? I don't see screens like in the HS series....


Kevin

There's screen the fuel passes through in those old ones and a sintered bronze filter in the newer (relatively speaking) ones.

A kit that generally fits the older ones is the RK-88 kit.

In case anyone can use one, attached is a parts list and diagram from 1966 for the HL's. Most of the PN's are obsolete though.

The 98A is in it.

I believe 1966 was the year I really started to notice girls.

Scott,

A saw should fire if you put a bit of mix through the plug hole despite many other possible faults unless you flood it.

A couple of things to check.

The odd plug won't fire under compression due to the increased air density but will fire fine outside the cylinder. It seems a lot worse to me since the end of leaded gas.

The other is timing. I believe you have other XF saws.
Compare the location of the magnets on the flywheel at TDC relative to the coil laminations on that saw and one of your other ones to see if the location is the same. It doesn't take much of a shift before the saw won't fire.

I see #17 as the fuel strainer screen...pretty big, probably not easily plugged. I'm not seeing the 98A...just the 97A & 101A and no mention of Jonsereds applications.

I think Scott will find the issue as he compares to a running XF......if the carb swap doesn't work.

Kevin

The coil reads the magnet as it revolves around in a circle....so the position of magnet on the flywheel itself is important for timing....that it hasn't shifted and the position of the coil pickup itself has the correct gap relative to the flywheel. The lamination are the flat pieces of metal bonded to make the shape of the coil along with the copper wire wrap in the middle.

So compare the coil pickup gap on a running saw to this XF and locate the magnet position on the flywheel in relation to a fixed point on the flywheel......like the key way. They should be identical on both saws.

This is only relevant if the timing is off....I'd do the carb swap first, because this involves pulling flywheels to check magnet positions.

Kevin

Correctly called the armature. Pic here show one with two legs yours very likely has three. I usually use some part of that as a reference point to see if the flywheel has slipped. It easily happens when people use oil on the taper of the crank.

View attachment 734902

Scott, looks like most of the flywheel magnets in these ported J'red's are glued into tightly milled recesses inside the flywheel. Really no place to slip around like in larger small engines.....they could get loose from losing their bond, but that's about it. I would suspect the XF is the same? I guess I've never had a magnet issue per say, on a saw yet...seen plenty of issues on larger small engines though....lol.

Like Tim said, make sure someone didn't get oil on the flywheel shaft and cause the flywheel to slip from its factory position. Be sure to try a ferrous piece of metal against the flywheel where the coil would pick up....there should be a good amount of pull on your metal piece.

Try a different carb yet?

Kevin

Fellas -

Thanks for all the input and sorry for my tardy response. Been busy working on Fairlanes, riding mowers, Alfa Romeos, vintage vises, a new welding table, and setting up the garage in the house we're about to move in.

Will take another look at it this weekend.

Thanks,

Scott

 

[Real1shepherd]

Well hell, Scott....that sounds like more fun than saws....lol!

Somebody gave me a Husky riding mower. Tim said that he's heard guys complain about the rear axle carrier developing cracks. Supposedly, all it needs is a new battery.....price is right. I still have to trailer it home.....

Kevin

 

[bulletpruf]

Well hell, Scott....that sounds like more fun than saws....lol!

Somebody gave me a Husky riding mower. Tim said that he's heard guys complain about the rear axle carrier developing cracks. Supposedly, all it needs is a new battery.....price is right. I still have to trailer it home.....

Kevin

Yeah, someone gave me a Troy Bilt mower. Only a few years old but wouldn't start. Did a bit of electrical work and threw a new carb on it. Runs like new.

 

[Real1shepherd]

Yeah, someone gave me a Troy Bilt mower. Only a few years old but wouldn't start. Did a bit of electrical work and threw a new carb on it. Runs like new.

I don’t know who makes TroyBilt now, but the marque lost all its glory. I had two TroyBilt weed eaters in the last eight yrs or so.....junk. Finally broke down and bought a commercial Stihl weed eater.....end of problem.

One of the TroyBilt’s was 2 cycle, the other 4 cycle. Neither one held up well....parts crazy high too.

However, I have a ‘79 Horse tiller that’s still going and I used it commercially for decades hiring out for gardens and reseeding. THAT’S a TroyBilt......lol!

Kevin

 

[Cantdog]

Hey Kevin!! I'm a lot closer to you than usual......out here inspecting your trees LOL. Not to near you but in Oregon.....waking up this morning in Pacific City and heading all the way down the coast eventually getting to Arcata then back up to Crater Lake then Mount Hood. First time in the PNW.....and just as awesome as I imagined it to be!!!

 

[Real1shepherd]

Hey Kevin!! I'm a lot closer to you than usual......out here inspecting your trees LOL. Not to near you but in Oregon.....waking up this morning in Pacific City and heading all the way down the coast eventually getting to Arcata then back up to Crater Lake then Mount Hood. First time in the PNW.....and just as awesome as I imagined it to be!!!

Be sure to check out some rain forests....try to find some OG Doug Fir stands...pretty spectacular stuff!

The guy that made all those videos; the chainsaw guy....has a shop on the coast. Rich Dougan, Myrtle Creek Saw Shop/Myrtle Creek, OR. He's retiring unfortunately, so don't know what his hrs are. Not exactly a tourist destination, but sure would be for one of us! LOL!

Kevin

 

[heimannm]

I was able to visit Wayne Sutton yesterday in Amboy, WA. He does not have a lot of Jonsered saws, but this one is special as it was the subject of the Chainsaw Age magazine documentary on how to build a hot saw.



Wayne outside his museum.



And just to prove that I was really there...



I saw a lot of big trees as well...

Mark

 

[Kensie1988]

I have an issue, it's the 82 issue I believe that has a segment of that hot saw build

Sent from my E6810 using Tapatalk

 

[Real1shepherd]

I was able to visit Wayne Sutton yesterday in Amboy, WA. He does not have a lot of Jonsered saws, but this one is special as it was the subject of the Chainsaw Age magazine documentary on how to build a hot saw.

View attachment 736957

Wayne outside his museum.

View attachment 736958

And just to prove that I was really there...

View attachment 736959

I saw a lot of big trees as well...

Mark

I made a lot of money in those big trees.....but regrettably, the timber was getting smaller, factions were pushing the EPA to de-tune/regulate saws for the first time and the Forest Service was making it harder for fallers to make a living. I saw the handwriting on the wall......at least within the Forest Service saleable timber structure. Then when I moved to CO, fallers were pretty much glorified tree thinners for the Forest Service.

Doesn't mean I don't miss it....I do!

Kevin

 

[Real1shepherd]

Just as an FYI, somebody is dumping a lot of used & NOS 80 parts on the bay. No deals, but if you absolutely have to have something and you've been looking for a long time, check it out.

Four pages of parts when there's usually one -two pages.

Kevin

 

[Cantdog]

Ouch!!!!!

https://www.ebay.com/itm/vintage-ra...944296?hash=item1a7c61f568:g:bMoAAOSwEnVc4swU

 

[Real1shepherd]

Ouch!!!!!

https://www.ebay.com/itm/vintage-ra...944296?hash=item1a7c61f568:g:bMoAAOSwEnVc4swU

That’s insane.........but the seller will probably get it.

Like the plastic top covers for the Husky 2100.....if it’s primo, ask whatever you want......lol!

From our old friend Kevin in SK......

Kevin

 

[Real1shepherd]

I will say that with Kevin in SK, he'll often take a reasonable offer....worth a try if you really need the part.

Kevin

 

[svk]

Hi guys. What do I have here?

 

[Neat_Hedgehog]

Hi guys. What do I have here?

Nice looking 621. A little weather checked, but pretty solid.

 

[svk]

Nice looking 621. A little weather checked, but pretty solid.

Awesome! Thank you!

 

[Real1shepherd]

Been outa town....'well purposed' 621. You can usually tell by the handle sheathing color.....I don't remember seeing another model with that same color.....plus I have one....lol.

If you're gonna use the saw a lot, find the felted round AF and the different AF cover/screw for it. That copper screen mesh is terrible for letting fine particulates in. The cylinder coating is very hard, but still.

Unless you know its history, I'd change the crank seals right away. Lots of people are toasting their jugs & pistons on vintage saws now because the old original seals are giving way.

That pull handle looks a bit 'gummy' too....lol.

Kevin