Jonsered Chainsaws

[Cantdog]

Actually the thin ring set up was pretty hot........on paper......really the fault with them (besides now being NLA) lay in the oil and tuning/mixing of fuel at the time they were current. The "more oil is better" theory killed them quickly as the rings being thinner they has less "memory" and stuck in the lands easily from carbon build up. The theory behind them was that using two thin rings you reduced the friction to about the same as one 1.5mm ring but gained in the fact that there are two opposing end gaps to lessen compression blow by, increasing compression and with two spaced rings increased heat transfer to the cyl walls more efficiently than a single ring. I have a 630 V with the original thin rings that was in good condition when I got it but I took it apart and cleaned the ring groves, checked the end gap and put it back together even though I had bought a new Meteor piston for it. It is the fastest stock 630 I have...but I run only Stihl Ultra at 50:1 same as every other saw I have......not a big Stihl flag waver but have been sold on Ultra for quite a long time......probably there are as good or better synth oils to be had but I can get this right in town at a very reasonable price....and even with high hours you don't see hardly any carbon deposits......even in the ex port. The thin rings work excellent but there is very little fudge factor with them.......and for a saw design to be successful the general public requires a sizable fudge factor......thin rings failed there. Like giving Mr Magoo a Ferrari....

 

[Just a Guy that cuts wood]

Be careful you don't get stuck with a 'thin ring' 630....J'red was fooling around with thin rings for awhile and let's just say....it didn't work out...lol. You'll never find the rings either, unless they're NOS.

How come you got a hankering for a 630?

Kevin

I thank for my size 61cc on a 20 inch saw is the best power to weight set up . Not all 61 cc are =
3700 Poulan has chrome bore 3800 does not .
If I only had one saw that would be it. Now I have this 80/90 jonsereds and was so impressed with it I needed to try another
Enter the 801 . I could get used to this (really) but the go to saw is Green .
Just thinking I should look but compare apples to apples
I may need to collect more J-reds

 

[Real1shepherd]

Actually the thin ring set up was pretty hot........on paper......really the fault with them (besides now being NLA) lay in the oil and tuning/mixing of fuel at the time they were current. The "more oil is better" theory killed them quickly as the rings being thinner they has less "memory" and stuck in the lands easily from carbon build up. The theory behind them was that using two thin rings you reduced the friction to about the same as one 1.5mm ring but gained in the fact that there are two opposing end gaps to lessen compression blow by, increasing compression and with two spaced rings increased heat transfer to the cyl walls more efficiently than a single ring. I have a 630 V with the original thin rings that was in good condition when I got it but I took it apart and cleaned the ring groves, checked the end gap and put it back together even though I had bought a new Meteor piston for it. It is the fastest stock 630 I have...but I run only Stihl Ultra at 50:1 same as every other saw I have......not a big Stihl flag waver but have been sold on Ultra for quite a long time......probably there are as good or better synth oils to be had but I can get this right in town at a very reasonable price....and even with high hours you don't see hardly any carbon deposits......even in the ex port. The thin rings work excellent but there is very little fudge factor with them.......and for a saw design to be successful the general public requires a sizable fudge factor......thin rings failed there. Like giving Mr Magoo a Ferrari....

I think that same scenario/story could be said about most of the older two thin ring piston experiments. I can especially relate to the Husky 2100 thin ring, which is now heralded as a 'Holy Grail' saw. Maybe if we had had a modern syn like Ultra, the saws would have held up better....or maybe it was just not a design to evoke longevity in a pro commercial setting. In any event, I wouldn't have one and they sure don't deserve their premium status today.

I use Ultra @40:1, but glad you said you use it fine @50:1. I'm not having any carbon/coke issues...maybe I'll move up to 50:1. In my loggin' career, we almost to the last man used Bailey's Power Punch. It was/is a quasi-synthetic oil mix.....probably the first one out there. The big pro saws I've broken down that used that @40:1, look damn nice internally. But I think Ultra is the way to go now for old & new...not a Stihl fan either, but nobody makes a better syn mix.

Kevin

 

[Kensie1988]

Evening guys, so I got fed up with another saw and set it aside. So I scrubbed the contacts and got nothing, so I pulled the flywheel too see what kinda shape the SEM was in. I took pictures. What do y'all think?

 

[Real1shepherd]

The leads just look dirty...clean them up and check for breaks or irregularities. Is that off your 70E?

Kevin

 

[Kensie1988]

Yes it is, it kinda caught me off guard because I was expecting a small ignition module.

 

[Real1shepherd]

Back in the day(toast!) there was a test box thing for SEM modules some Husky dealers had. I don't remember if it could flag modules with 100% accuracy. Today, most everyone just substitutes with a known good module like it....can be expensive to find SEM modules even used.

Kevin

 

[Kensie1988]

Well I guess I will eventually find one, I will clean that one up, but I can see breaks in the insulation, and there looks like some sort of black silicon or something on it.

 

[Kensie1988]

Also if anyone knows of a know working module with low hours, I would be willing to pay for one.

 

[Real1shepherd]

I'd take like a stout sewing needle, poke it through the insulation near the module and check continuity on ea wire end.

Kevin

 

[Kensie1988]

i apologize for my ignorance but how do I check continuity and what is the needle for?

 

[SawTroll]

Not familiar with that family of J'reds...newer than anything I have....close link or clone of Husky? Check all your wires coming off the module in that they haven't lost insulation and are maybe touching. Pull the wire off that goes to the kill switch and see if that makes any difference.

Let others weigh in on the reliability of those particular modules. Seem to be plenty of them on eBay, sawagain.com etc.

Kevin

No, that "family" of Jonsered saws are not "clones" of any Husky model - as far as I know they are Jonsereds own design. Production is a different story though, as far as I know they were made at the Partner factory up to 1987, then at the Husky factory for a some years.

There were no Partner or Husky versions of those saws.

 

[Just a Guy that cuts wood]

i apologize for my ignorance but how do I check continuity and what is the needle for?

You need a multimeter with a tone setting when you touch the two ends together a tone will sound (continuity)
I use long stick pins
I also use alligator clips on the pins so I can move wire around to cheek for brakes

 

[Just a Guy that cuts wood]

You need a multimeter with a tone setting when you touch the two ends together a tone will sound (continuity)
I use long stick pins
I also use alligator clips on the pins so I can move wire around to cheek for brakes

Pierce the wire at each end listen for tone Sorry I left that off lol

 

[Kensie1988]

I'm having a hard time visualizing this process because I am not familiar with electronics at all. So I stick the needles into the wires at each end then touch the multimeter to each one? What setting does the multimeter need to be on?

 

[Real1shepherd]

I'm having a hard time visualizing this process because I am not familiar with electronics at all. So I stick the needles into the wires at each end then touch the multimeter to each one? What setting does the multimeter need to be on?

You'll either have near 0 ohms on your multimeter or the test beep that tells you automatically that there is no break in the wire...you have continuity....that's all we're testing for here. If you don't have the continuity beep tester than a break in the wire will cause the ohm reading to go towards infinity.

I'm saying to needle probe near the module because through the module may give erroneous readings...dunno without having one in my hands. This way you're testing the majority of the wire itself before it goes through the module. Not likely to have a break from where you needle probe to inside the module. Don't need a needle on the other end...just touch or clip on with your multimeter's other probe. So....clip one probe(doesn't matter which) to the needle and the other to the end of the wire.

Use the lowest ohm setting on your multimeter...you're going for maximum sensitivity.

Kevin

 

[Kensie1988]

Ok I think I got you now. The wires are kinda exposed where they go into the module, it appears that someone may have put some sort of silicon or something down there trying to cover it. Do I need to clean all of this out and re wrap the wires with some sort of tape? Or do I need to re silicone it back up?

 

[Kensie1988]

So I stuck a needle in up close to the module and another towards the end and took readings, on both wires the numbers jumped erratically from 0-190 back and for up and down that range

 

[Real1shepherd]

So I stuck a needle in up close to the module and another towards the end and took readings, on both wires the numbers jumped erratically from 0-190 back and for up and down that range

You might be getting feedback from the module...or you're not making the best connections with your probes. A fluctuation with good connections would indicate feedback from your module's components(like from a capacitor). If you can get the reading to stabilize at 0 by pressing hard and staying around 0, then your wires probably have continuity.

There's a marine grade of that liquid insulation stuff you can use....or you can silicone and heat shrink if necessary.

Kevin

 

[Kensie1988]

You might be getting feedback from the module...or you're not making the best connections with your probes. A fluctuation with good connections would indicate feedback from your module's components(like from a capacitor). If you can get the reading to stabilize at 0 by pressing hard and staying around 0, then your wires probably have continuity.

There's a marine grade of that liquid insulation stuff you can use....or you can silicone and heat shrink if necessary.

Kevin

Gotcha, I might not be getting a good connection, I'm not sure where best place to place those probes are along the needle, up against the wire insulation or further out along the needle?