Jonsered Chainsaws

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Thanks WW - the description he gave me certainly describes the older style. If and when I get hands on the saw I will certainly try the Atom or Nova modules to see if we can get a spark.

Mark

Ahhh.... my bad Mark...I thought you were talking about the late style ign so that was what I answered. The Atom won't help on the early style.. WW caught that but didn't get the terminology just right. On the early ign the module is under the flywheel and the actual spark coil is in the recoil cover. These modules fail but there are a couple things to check and another remedy perhaps. There are two low tension wires the exit the module in the same location.....the insulation fails right here.....I've had luck separating them and coating them both with marine grade liquid tape to create an insulation barrier. Another item on these saws is the connection between the module and the coil.....this is made by two brass "buttons" simply touching each other when the recoil is bolted on. There is one in the case and one in the recoil cover....these lose connection through oxidization and/or wear. I usually clean everything up and slip one of the wavy washers that comes on the Jonsereds recoil bolts and elsewhere between the connectors held in place with a dab of grease. If none of this works there is one other thing.....this 70E module is the exact same module as used on the 52E......however they carry different part #s due to different wire lengths. So you can be on the prowl for either one......or even a parts saw that has spark.....
 
I picked up a good used 2166 at the local John Deere Dealer the other day. I got to thinking about it on the way home how it is a similar deal as the 70e/66e. Luckily this 2166 is not the dud that the 66e is. I haven't decided if I'm going to do the 2172 transfer modification, but for $200 it's a hard deal to beat.
 
I picked up a good used 2166 at the local John Deere Dealer the other day. I got to thinking about it on the way home how it is a similar deal as the 70e/66e. Luckily this 2166 is not the dud that the 66e is. I haven't decided if I'm going to do the 2172 transfer modification, but for $200 it's a hard deal to beat.

I ran Jack Walker's ported 75cc 2171 at a Moss Man's GTG and I gotta say it was the nicest modern Jonsered I've ever run.....Woodchucker had a 372 with the exact same set up built be the same guy and it was tuned perfect...Jacks was a bit fat so wasn't quite as fast but felt way better to handle....and I think the same performance was only an eighth turn away!!!
 
Commemorating this past weekend with the first tree I got to cut with the Jonsered 801 since I pulled it from the scrap heap. 21-22" hemlock out back where we're clearing space for a polebarn.

Although hardly the first tree it has cut in its previous lifetime, I'm quite sure.

IMG_20180811_102508.jpg

Also, dad for scale.

IMG_20180811_101704.jpg
 
Snagged a late 70e aluminium flywheel, cylinder, coil and chip on eBay. Only needed the flywheel really but the rest is good to have on hand.

Would still like to figure out a windowed piston like a 10mm 044 but that's for another day.
 
I'd put it in the 'meh" category. I wouldn't seek one out, but I wouldn't turn one away. I ran someone else's trying to sort it out for them and the oiler seemed marginal. It's not a pro quality top handle saw, but it's light and well balanced with a 12" bar (I think that's what it had).
 
I did get the 70E last weekend. Very clean looking saw but the compression is low even with a new ring. Cylinder looks great, piston has some wear but hard to explain only 130 PSI compression.

20180823_122511.jpg

This is before I did any work or cleaning on the saw.

20180820_195902.jpg

20180820_195937.jpg

The wires in the module had been crimped badly when someone didn't route them through the passage and both literally fell off in my hands. I soldered them together again and used some heat shrink tubing plus some liquid tape to secure the connections.

20180823_142735.jpg

The connection between the module and the coil seems to be good, and I do have spark now. I used my drill to spin it over from the clutch side and while it is not a bright, snapping spark it does have spark.

20180823_142728.jpg

None the less, no joy getting it to run. I did pressure and vacuum check, there did seem to be a vacuum leak in one spot as I rotated the crankshaft so I replaced the PTO side seal and that solved the vacuum issue. I also went through the carburetor, replaced the fuel pump gasket & diaphragm, the metering diaphragm was fine. Carburetor checks O.K. with a pressure test.

I did get it to pop a few times by priming it through the carburetor but it didn't seem to be pulling any fuel which led me to go through the carburetor. After that I couldn't get it to pop at all. I even tried a different spark plug but no difference. Is 130 PSI too low to expect this saw to run? Have I missed something more obvious?

I will check the spark with the drill again tomorrow, it did seem to be iffy as I was cranking it over by hand. If it never runs it will still look good up on display when I get my museum built, but is seems a shame for such a nice looking saw to not get run at a GTG or something.

Mark
 
It should start that's about the same I got on a fresh vec piston. Get a couple tanks on it probably come up a little.

Carb base gasket original or out of the kit? The one from the kit doesn't fit usually. Leaves part of the trough exposed just enough to lose impulse. Cantdog has posted about it a few times.

I chased my tail on that a while back and literally read this entire thread looking for the fix. Which is basically cut your own gasket.
 
If it's a Tilly, the correct carb to manifold gasket is still available as a Husky part. It's a green gasket and covers the impulse channel as it should. I'm pretty sure I posted the gasket # a few times.

Although not ideal, the saw should run OK @130psi. Looks like someone omitted the clylinder base gasket and used RTV sealer. Not a big fan of that scenario.

Kevin
 
Again...no notifications that anything was going on in this thread. Been down that road before....should have checked.

Hit 113F here a couple of weeks ago. Been living in smoke since then. Trip to Portland a week ago and witnessed two fires they were putting out set from the hwy. One went up a small canyon and they were working it with water planes and a heli.

So now they're trying to figure out the long term effects of breathing smoke everyday....lol. I have to quit early afternoon some days....just too much to take. We're supposed to get a 'cold' front tommorow and the smoke clear some.

They caught the guy that set the Holy Fire in CA. Looks like an immigrant...let's not go there...lol!!!

Kevin
 
Nice looking 70E Mark......couple questions.....did you replace the ring yourself or did it come to you that way? Sixone already brought up the carb gasket issue and that certainly is a thing to check on. Kevin also brought up the red silicone on the cyl base.......I am almost an anti-silicone Nazi....it should never be used on any saw IMHO..... there are much better sealants available. My own preference is Hylo Mar Blue. Anyway there is a very real possibility that some of that goop has plugged your impulse corridor.....that'll kill fuel pumping dead in it's tracks.....another thing to double check. 130 is pretty low but she should start on that if fuel and air are present.....eliminating the base gasket on any of the old Jonsereds is not terribly helpful as once compressed the thin paper gaskets only takes up 0.004-0.05" so you don't gain much of a compression boost at all.....
 

Latest posts

Back
Top