Jonsered Chainsaws

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on the 90, when I bought it, I didn't try to start is as I didn't want to suck the stinky years old fuel into the carb or engine. I did hang it from the starter handle and did pull slowly a couple of times and there seemed to be quite a bit of compression. but when I removed the starter just now, the engine is very easy to turn over by turning the flywheel with my hand. not as easy as when I push the compression release in but pretty easy. with the compression release in, turning by hand I can hear the compression bleeding off. with the compression release out I don't hear any compression bleed off.
 
haven't started the 621 in a few months. went to do that and pulled the handle off the starter rope. rope is only 21" long. does anyone know if that is correct? feels short pulling it. thanks!
went to install the new starter rope and handle on the 621 and broke the f#@king return spring. damn. I was able to bend a new hook on the spring but after starting the saw twice, the new hook straightened out. is it possible to bend a new hook and harden it by heating just the hook to red and cooling it in oil like a knife? anyone know?

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If it's the 'real deal', it will be for 10mm bar studs. The PO could have filed the inside of a Husky bar to make it fit. I think I only have one authentic 36" bar for the older Jonsereds big cc saws. The older Large Husky bars were pretty close(sloppy machining from the factory) or easily altered.

If he finds the old bar and it's .404, I'll buy it from you if ya wanna sell.

Kevin
the 24" bar on the saw is a Tillotson. had no idea they made chainsaw bars. is this the same Tillotson that made carburetors?
 
the 24" bar on the saw is a Tillotson. had no idea they made chainsaw bars. is this the same Tillotson that made carburetors?
Never seen that on a bar. If it's spelled exactly the same, I'd have to assume so, although I doubt they made the bar. Branding/badging thing......

Maybe I've seen that on the Net...I dunno, I'm old and few things impress/shock me these days....lol.

Kevin
 
went to install the new starter rope and handle on the 621 and broke the f#@king return spring. damn. I was able to bend a new hook on the spring but after starting the saw twice, the new hook straightened out. is it possible to bend a new hook and harden it by heating just the hook to red and cooling it in oil like a knife? anyone know?

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You're changing the dimension of the spring....I wouldn't. Plenty of NOS springs out there. Try the sources I mentioned earlier. Jonsereds was great about sharing the same parts all the way through 'families' of saws.

The end of springs are sometimes heat treated, sometimes not. Best to look at a NOS spring and see. That can make them too brittle and they break easier....it's an engineer's design choice.

If you're gonna heat it; cherry red to oil...let it cool and then heat to straw and air cool.....it won't be so brittle.

Kevin
 
on the 90, when I bought it, I didn't try to start is as I didn't want to suck the stinky years old fuel into the carb or engine. I did hang it from the starter handle and did pull slowly a couple of times and there seemed to be quite a bit of compression. but when I removed the starter just now, the engine is very easy to turn over by turning the flywheel with my hand. not as easy as when I push the compression release in but pretty easy. with the compression release in, turning by hand I can hear the compression bleeding off. with the compression release out I don't hear any compression bleed off.
You're not gonna know for sure until the saw is back together, choke off, throttle wide open and do a compression check. Anything over 150psi is good for work. Anything over that is longevity gravy.

The saw doesn't have enough hrs on it for carbon buildup most likely. If you have a cam, run it down in the cylinder. If you're not getting at least 150 psi in that saw, suspect the decomp or a seal leak first. Personally, I wouldn't trust those old crank seals. They age whether you're using the saw or not....inactivity dries/shrinks them out too.

Lots of classy old saws have been ruined in just a tankful because they thought the seals "should be OK".

Kevin
 

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