Jonsered Chainsaws

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It's much like the Husky design; you have that large O-ring to replace and the inner seal in the oiler housing needs to be coaxed onto the shaft with like a tall socket so it doesn't fold outward. Some mix oil on the inner part of the seal. Ensure there are NO burs on the shaft when you coax that inner seal/housing on.

Take note when you punch out the old inner seal of its position and replace it with a new seal in the same position. Lube the large O-ring with mix oil as well.

I would clean the exposed bearing with saw mix....just like you run the saw with and a good parts brush until you think it's clean. If the P&C was off, I'd also 'wash' the inside case with your saw mix until it was 'clean' as well.



Kevin
 
It's much like the Husky design; you have that large O-ring to replace and the inner seal in the oiler housing needs to be coaxed onto the shaft with like a tall socket so it doesn't fold outward. Some mix oil on the inner part of the seal. Ensure there are NO burs on the shaft when you coax that inner seal/housing on.

Take note when you punch out the old inner seal of its position and replace it with a new seal in the same position. Lube the large O-ring with mix oil as well.

I would clean the exposed bearing with saw mix....just like you run the saw with and a good parts brush until you think it's clean. If the P&C was off, I'd also 'wash' the inside case with your saw mix until it was 'clean' as well.



Kevin
Thanks Kevin for the tips. I found a few videos showing replacement of the clutch seal on a 288 as a guide, any other husky saws with that setup that I could lookup?

Is the worm gear pressed on or threaded? How do I remove it? I tried to pull it but it didn't want to budge and I was afraid of damaging the threads if I used any tools.
 
I cleaned up the 751 in preparation of moving it to the display. The bar that was on it was not a proper fit so I found a suitable one (hardnose).

20240501_172753.jpg

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As much as I would like to run it in some wood, I don't want to go through the clean up again so for now anyway, I will have to be satisfied with just hearing it run a bit.

With that done, I decided to have a look at the 621 that came in at the same time one one thing led to another...

20240501_152900.jpg

There was a leak at the base of the cylinder so I pulled it, cleaned everything up well, and put it back together with some Threebond.

Mark
 
Eric prolly has the old promo lit for J'red concrete saws. I've seen them in the past. Yeah, I knew a guy who had a 70e concrete saw and converted it to a chainsaw. Not to put down the effort, but I'd have nothing to do with a concrete saw that had been used. If there was anything ever truly 'disposable' or something to rent only, that was it.

Kevin
Somehow or other I ended up with one, decent shape for what it is...

mk70 l.JPG
 
I cleaned up the 751 in preparation of moving it to the display. The bar that was on it was not a proper fit so I found a suitable one (hardnose).

View attachment 1174072

View attachment 1174073

View attachment 1174074

As much as I would like to run it in some wood, I don't want to go through the clean up again so for now anyway, I will have to be satisfied with just hearing it run a bit.

With that done, I decided to have a look at the 621 that came in at the same time one one thing led to another...

View attachment 1174077

There was a leak at the base of the cylinder so I pulled it, cleaned everything up well, and put it back together with some Threebond.

Mark
Blown cyl base gaskets are real common on those.....they only measure about 0.007" once compressed...bolts get lose and away they go!! They can last forever as long as the bolts remain tight.
 
Hey Bill, How are the air filters on that old rig?
Hey Robin,
Filters are actually all there and decent shape. Typical paper pleated sleeves, an inner and outer, then a flat foam sheet on the bottom that feels like its starting to deteriorate but still holding together. I don't recall if I ever started the thing, now I'm curious, when I first acquire anything like that I usually at least squirt some gas on the filter and give it a few pulls.

Label riveted to the wheel guard calls it out as a "Jonsereds Carb Cutter MK 70", not sure what that's about...

mk70  r.JPG
 
Hey Robin,
Filters are actually all there and decent shape. Typical paper pleated sleeves, an inner and outer, then a flat foam sheet on the bottom that feels like its starting to deteriorate but still holding together. I don't recall if I ever started the thing, now I'm curious, when I first acquire anything like that I usually at least squirt some gas on the filter and give it a few pulls.

Label riveted to the wheel guard calls it out as a "Jonsereds Carb Cutter MK 70", not sure what that's about...

View attachment 1174107

Carb as in carborundum blade- dry saw not a diamond blade wet saw?
 
I cleaned up the 751 in preparation of moving it to the display. The bar that was on it was not a proper fit so I found a suitable one (hardnose).

View attachment 1174072

View attachment 1174073

View attachment 1174074

As much as I would like to run it in some wood, I don't want to go through the clean up again so for now anyway, I will have to be satisfied with just hearing it run a bit.

With that done, I decided to have a look at the 621 that came in at the same time one one thing led to another...

View attachment 1174077

There was a leak at the base of the cylinder so I pulled it, cleaned everything up well, and put it back together with some Threebond.

Mark
So you got the 751 running? I haven't had time to go through mine but am looking forward to. For an older, non-AV saw they are a surprisingly compact power head. I use my 601 occasionally and am always amazed how smooth it is for a non-AV unit. I've yet to actually run a 751 myself but am hoping it works similar to the 601.
 
Mark had mentioned George Blake; this is George selling this saw. I bought one of his saws on Ebay a short while back, and he is certainly a gentleman as Mark said.

Thanks for that information Jay, I will get serious about that saw on Saturday...

The 751 was easy, fix the starter, fix the choke, add fuel, start and run. As you can see, I was very close to my test log but somehow resisted the temptation to get the saw dirty again.



Mark
 
Thanks Kevin for the tips. I found a few videos showing replacement of the clutch seal on a 288 as a guide, any other husky saws with that setup that I could lookup?

Is the worm gear pressed on or threaded? How do I remove it? I tried to pull it but it didn't want to budge and I was afraid of damaging the threads if I used any tools.
Husky 2100 is similar as well for that design.

Unless your worm gear is damaged or you're splitting the case, I'd leave it alone. It appears pressed on looking at and feeling it, but I dunno.....never removed one of mine because I haven't had to split the case or seen any damage.

Kevin
 
621 is back together and runs well. I will need to find another clutch or spring, as the idle speed must be so low to keep the chain from moving that the engine wants to stall out. I did risk getting this one dirty cutting in my test log. Not bad for a 56cc saw.

Before...

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After...

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Mark
 
621 is a great saw....can last forever, built like a tank. I've got one waiting for me in about this potential shape. If you're gonna run it a lot, toss that copper screen filter and put in the flocked one with its own correct cover.

It was my goal to semi-retire, build a workshop in my garage, and among other things, work on saws. Great setup, Mark!

Kevin
 
Caber has you covered for rings. Piston and boot will be used. Lots of places to try for that, each with its own set of problems.

I wonder if the same intake boots are shared between the 910/920/930? If so, you can add two more models to your search.

Kevin
I just saw this. And I can confirm the boot is the same for all three (and the boot "holder" is also interchangeable between the three models), I was able to find a new one on fleabay actually, and I'm currently sitting on three total. All I need is one, and would like to keep a spare. All are in good condition. @heimannm Still need one?
 

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