Jonsered Chainsaws

[svk]

66 or 70 cylinder?

 

[taplinhill]

66 or 70 cylinder?

70e

 

[svk]

70e

Awesome, thank you.

 

[Real1shepherd]

Agreed!

Just kidding....I didn’t know the difference between those two...lol.

Kevin

 

[taplinhill]

Agreed!

Just kidding....I didn’t know the difference between those two...lol.

Kevin

Four. The difference between 70 and 66 is four.




.

 

[Real1shepherd]

Four. The difference between 70 and 66 is four.

Good one!
Now would that be just numbers or cc’s?

Kevin

 

[taplinhill]

Good one!
Now would that be just numbers or cc’s?

Kevin

Just numbers. I believe the 66e is 61cc and the 70e is 69cc.
The 66e is a real turd.

 

[Real1shepherd]

Well, they sure bounced back with the 70e. I’ve never heard anyone talk about owning the 66E.

Kevin

 

[albert]

66 has 2 rings, 70e has 1.

 

[Cantdog]

Yep......most of what has been posted is correct. The 66E does have two rings whereas the 70E has but one and the 66E also has one more cooling fin than the 70E. Easiest way to tell is pull the muffler and see how many rings or measure but measuring is rather unnecessary due to the number of rings. I'm with Eric......My guess would be 70E due to the looks of the fairly wide spaced fins......another observation to bolster that guess is the raised top of the engine cover. This is to allow for the plumbing/fittings of the Nordfeller attachment. I don't believe the 66E ever came equipped with this feature. Not all 70Es were set up for this either and when not the top cover is flat. But as usual the best way too tell for sure is to simply pull the muffler and see how many rings it has. Who knows what covers/etc have been swapped over the years.....

 

[Cantdog]

Another quick way to help identify the three versions of the 66E and the two 70E models is if the serial number is above or below 158500. With the lower number one having the plastic fan/SEM ign and the later ones with the aluminum fan and cyl mounted coil. I see this one is way below that threshold and I believe the 66E was discontinued before the number break.

 

[J D]

Now that's the good news.....the issue lies between the wrist pin bosses. The clearance between the upper conrod sides and the bosses is excessive. In the thread I gave all the actual measurements. In these motors the wristpin to conrod measurement is what centers the lower conrod bearing on the crank journal and keeps the rod from rubbing on the counterweights....on the pro Jonsereds saws of the time this was controlled by accurately cast and machined pistons and thrust washers on either side of the upper rod bearing.....generally measuring a running clearance of around 0.012-0.014". The 49sp being semi pro (spelled economy) saw did not do it this way but simply cast the bosses closer together, eliminating the thrust washers and using a narrower bearing, giving a running measurement of like 0.030" + or -...........the VEC piston designers didn't think about this aspect of the piston and the clearance measures a lot more......I can't remember exactly (it's in the thread) but something like 0.165- -.200" or whatever......enough to allow the codrod big end to shift back and forth enough to rub on both counterweights. I cured this by installing the upper conrod bearing (wider bearing) and thrust washer set from a 52/52E ...this required me to remove about 0.015" from each boss face....I did this carefully with a dremel but it would be better done with a mill......anyway this gave me about a 0.012" running clearance. This also will make this piston a suitable replacement in a 52/52E as well......

The first pic is of the VEC piston with the 52/52E wider bearing and thrust washers installed...

View attachment 405794

I have a similar issues with a Husqvarna 350 & an aftermarket piston. Do you know what material the thrust washers are? I'm tossing up between making them out of steel or brass. Cheers

 

[mogulmasher]

Well, it has been awhile but I am trying to fix/replace broken vent valve on my 2095 again. I thought a couple times I had part sourced only to have the vendor come back and say it is NLA. Somebody on here suggested it was maybe pipe thread. Looked to be about 3/8" (-06) pipe thread, so I found a fitting and tried it. It only goes in half turn before it binds up. Maybe it is just regular metric thread? Looks like it is possibly M14 x 1.5? Does anyone have an idea? Maybe it is some sort of European pipe thread? It was sealed with an o-ring which leads me to believe it is straight threads and not tapered pipe, but I dunno?

 

[Woodslasher]

Sounds like it’s metric. The 1/2 turn before sticking is metric’s trademark. It starts threading in and you have enough time to think, “Yes, this random bit of hardware will work!” before it seizes and you start cursing at it.

 

[Real1shepherd]

Well, it has been awhile but I am trying to fix/replace broken vent valve on my 2095 again. I thought a couple times I had part sourced only to have the vendor come back and say it is NLA. Somebody on here suggested it was maybe pipe thread. Looked to be about 3/8" (-06) pipe thread, so I found a fitting and tried it. It only goes in half turn before it binds up. Maybe it is just regular metric thread? Looks like it is possibly M14 x 1.5? Does anyone have an idea? Maybe it is some sort of European pipe thread? It was sealed with an o-ring which leads me to believe it is straight threads and not tapered pipe, but I dunno?

I was only guessing on IPS thread. The difference between US IPS and Euro pipe thread is slight.....especially in this application. As I said before, you can take a US IPS pipe plug and screw it into the bar oil tank filler hole. I've even seen used saws come this way on the 801/80/90(and probably fits others as well).

Since you only got a half turn, you need to try metric no-taper bolt thread. It's probably not pipe thread after all.

Kevin

 

[mogulmasher]

Went through my metric bolt supply but have nothing large enough to try. I did find a metric nut that appears to be same thread. Gonna try and find a bolt/fitting tomorrow that will fit it. Of course even if I figure it out not sure where I'll find a metric barbed fitting that work for me.

 

[jonsereds 621]

Went through my metric bolt supply but have nothing large enough to try. I did find a metric nut that appears to be same thread. Gonna try and find a bolt/fitting tomorrow that will fit it. Of course even if I figure it out not sure where I'll find a metric barbed fitting that work for me.

Get your measuring gear out ! 1/4 BSPp at a guess.

 

[Real1shepherd]

As few threads as there are in the saw case thickness, it doesn't sound like it's BSPT.....but I could be wrong.

As far as the 'where' to get metric fittings....Amazon, baby!

Kevin

 

[Cantdog]

Nice looking early 90.....nice bar.....But...damn the price is way up there and then add $86.00 shipping......phew!!!!
I have to have my left thumb rebuilt this Dec......think while I'm recovering I should build a bunch of 80s and 90s, 910Es etc and ebay them.....have quite a few....and all the parts to make them go again...

https://www.ebay.com/itm/Vtg-Gas-JO...340135?hash=item366bf34967:g:RmwAAOSwKGRffxkG

 

[Cantdog]

Cool.....and here's a hat to go with that saw!!!

https://www.ebay.com/itm/1-Vintage-...905560?hash=item366bdd6598:g:H90AAOSwEMNdfcxz