Jonsered Chainsaws

[tmessenger]

How did the piston measure?? It's probably good but I've had pistons that looked great but in reality were worn out (0.012"-0,016" undersize) The realistic wear limit is about 0.006 under. You said it looked to have low hrs so it's probably fine. But you should check. Make sure you clean out any carbon from the ring groove and lands before you reassemble.

The piston is .002 under at the skirt .004 under just below the ring and .007 under above the ring were I worked it a little with 320 wet and dry to smooth up the light scorning on the exhaust side. Ring land has very little carbon but will clean it up as required. I like the way this saw is put together and love the look. Was surprised by the weight with a 16" b/c 17 pounds but then discovered both tanks were full and it has good sized tanks. Wonder how this one will run compared to a Stihl 031 I sold recently? they are from around the same vintage and have the same displacement.

 

[SawGarage]

The piston is .002 under at the skirt .004 under just below the ring and .007 under above the ring were I worked it a little with 320 wet and dry to smooth up the light scorning on the exhaust side. Ring land has very little carbon but will clean it up as required. I like the way this saw is put together and love the look. Was surprised by the weight with a 16" b/c 17 pounds but then discovered both tanks were full and it has good sized tanks. Wonder how this one will run compared to a Stihl 031 I sold recently? they are from around the same vintage and have the same displacement.

WOW...

that piston is NEW!!!


the crown is ALWAYS smaller, to allow for thermal expansion..

J

 

[Cantdog]

Yeah....with numbers like that you are good to go. Clean her up good and reassemble with a new ring and you'll have real solid, comfortable saw for general use. (of course I may be prejudiced!!!)

Don't know if you have a ring yet but site sponsor Northwoods Saw has nice Caber rings (44MM X 1.5MM) for $4.99. (SKU # PR656) These guys are great, very light shipping and stuff gets to you quick.

If it's been sitting for a while, you may want to rebuild the carb, new fuel line/filter and clean, match, set your points, with new seals this saw will last for yrs and yrs with proper tuning and quality fuel/oil.....yrs and yrs....

Sorry I can't speak for or against any comparison with any of the Stihl line.
No experience with them. However, as you may have guessed from my sig, I can and do speak from experience with the Jonsereds 49sp. First and only saw I ever bought new and that was 1977. Sadly that saw resides in the parts section for now. But it surely earned it's rest. But it is only resting up!! This winter (if I can find the time) I am planning a full tear down and rebuild and putting this saw back to the head of my line, where it belongs. It is suffering from a totally worn out piston and bent or missaligned crank shaft.

Jay....Are those NOS 44MM pistons you spoke of from Jonsereds??? If so, one ring or two????

 

[tmessenger]

Thanks for all the info. There was no carbon build up on the piston crown or exhaust port so this saw had been tuned lean at the carb and run that way for a while. I'll go through the carb, new fuel line, ring, fuel filter, crank seals and full clean up (par for the course with a saw this old). There was some fine sawdust in the crankcase so I'll also need to check the carb to air filter seal, the seal is there so must be leaking or the previous owner like to run really dull chains. When I get it back together I'll put up a photo and let you know what I think of the power compared to the Stihl 024 Super and 031

Tim

Yeah....with numbers like that you are good to go. Clean her up good and reassemble with a new ring and you'll have real solid, comfortable saw for general use. (of course I may be prejudiced!!!)

Don't know if you have a ring yet but site sponsor Northwoods Saw has nice Caber rings (44MM X 1.5MM) for $4.99. (SKU # PR656) These guys are great, very light shipping and stuff gets to you quick.

If it's been sitting for a while, you may want to rebuild the carb, new fuel line/filter and clean, match, set your points, with new seals this saw will last for yrs and yrs with proper tuning and quality fuel/oil.....yrs and yrs....

Sorry I can't speak for or against any comparison with any of the Stihl line.
No experience with them. However, as you may have guessed from my sig, I can and do speak from experience with the Jonsereds 49sp. First and only saw I ever bought new and that was 1977. Sadly that saw resides in the parts section for now. But it surely earned it's rest. But it is only resting up!! This winter (if I can find the time) I am planning a full tear down and rebuild and putting this saw back to the head of my line, where it belongs. It is suffering from a totally worn out piston and bent or missaligned crank shaft.

Jay....Are those NOS 44MM pistons you spoke of from Jonsereds??? If so, one ring or two????

 

[Cantdog]

Thanks for all the info. There was no carbon build up on the piston crown or exhaust port so this saw had been tuned lean at the carb and run that way for a while. I'll go through the carb, new fuel line, ring, fuel filter, crank seals and full clean up (par for the course with a saw this old). There was some fine sawdust in the crankcase so I'll also need to check the carb to air filter seal, the seal is there so must be leaking or the previous owner like to run really dull chains. When I get it back together I'll put up a photo and let you know what I think of the power compared to the Stihl 024 Super and 031

Tim

Well Tim the air filters on these saws only keep out the chunks. Just a single layer of fine mesh. If you get this running properly I think you'll find it'll keep right with up the saws mentioned. If the piston shows no scoring I wouldn't count on it running lean. Just perhaps good oil. I have a ported 630 that has two yrs on it and the piston top and EX port looks like the day I put it together. (Stihl Ultra) Don't know alot about their saws but do like that oil!!!

You'll find that this all metal saw is real solid feeling in your hands. They turn pretty well but are not the least bit buzzy or loud. It just feels like a very well made and thought out tool. Power isn't everything....handeling is just as important with these small saws.

 

[SawGarage]

.....It is suffering from a totally worn out piston and bent or missaligned crank shaft.

Jay....Are those NOS 44MM pistons you spoke of from Jonsereds??? If so, one ring or two????

Ugh!!! your gonna make me go look, huh??


what would the difference be?? might I ask???

J

 

[Cantdog]

Ugh!!! your gonna make me go look, huh??


what would the difference be?? might I ask???

J

Well...If they are for Jonsereds and 44MM, the crowned, single ring would be for the open port 49SP and the two ring with a slightly taller crown is for the closed port 52/52E. I know the two ring is 11 grams heavier but will work in the 49 with good results but have never put a 49SP piston in a 52. I expect it would work as they are both round, full skirt pistons. (no widows or flat sides) The cranks are the same part # s. I'll provide the Mahle piston #s. for each later today.

 

[briantutt]

Another one coming

I was talking to a cattle farmer that we get our pork from at church last Sunday. He asked me what I was doing after church. I told him "hiding in my basement tinkering with old chainsaws I find at garage sales, try to get the running" He said "I have one you can have. It's a Jonsereds...620 I think". I said "I'll take it"...He said "I will bring it next week, been sitting in my barn for years"...

What is a Jonsereds 620

 

[8433jeff]

I have a slightly used clutch cover I'll trade you for it. lol

 

[briantutt]

That made me laugh out loud...:biggrinbounce2:

 

[chucker]

im stumped!!

after 23 years of service im just not sure what to do?? the old jons 670 champ is idleing well but lost all its power/compression... ! new saw or rering the old reliable saw??? maybe trade it off for a wild fling hey!! please shoot me now before i make a green mistreak... lol

 

[Cantdog]

after 23 years of service im just not sure what to do?? the old jons 670 champ is idleing well but lost all its power/compression... ! new saw or rering the old reliable saw??? maybe trade it off for a wild fling hey!! please shoot me now before i make a green mistreak... lol

No question at all in my mind...new Meteor piston, set of crank seals, kit the carb, new starter rope and you're ready for another 23 yrs. If you're handy and can do the work yourself..you're looking at $50-$75 tops. Add $30 more if you want/need new AV mounts....what new 70cc saw are you gonna get for that money??? Nope, no question at all....Good luck..

 

[spike60]

I was talking to a cattle farmer that we get our pork from at church last Sunday. He asked me what I was doing after church. I told him "hiding in my basement tinkering with old chainsaws I find at garage sales, try to get the running" He said "I have one you can have. It's a Jonsereds...620 I think". I said "I'll take it"...He said "I will bring it next week, been sitting in my barn for years"...

What is a Jonsereds 620

It's probably a 621. A real good classic Jonny. Hope he doesn't forget it!

 

[J.Walker]

Some Jonsered advertising.

.

 

[chucker]

No question at all in my mind...new Meteor piston, set of crank seals, kit the carb, new starter rope and you're ready for another 23 yrs. If you're handy and can do the work yourself..you're looking at $50-$75 tops. Add $30 more if you want/need new AV mounts....what new 70cc saw are you gonna get for that money??? Nope, no question at all....Good luck..

THANKS CANTDOG!! this is what i wanted to hear but do you think the new seals are needed? it idles fine and dont miss a tune when reved to the maxx ... just no compression ?? lift the saw with bar and chain full of fulids by the rope and it justs bleeds down!!

 

[Cantdog]

No it may not need it right now but will before long. The 630 Super II in my sig I built from a very worn out carcase a couple yrs ago, did everything except the seals and ran great until this fall but now needs them. Not a big deal but if I had done them when the thing was all apart I wouldn't HAVE to now. I think when you are running a worn out top end the seals are not working with as much pressure and vac as when everything is fresh. That's when these things begin to show up more because good piston fit and ring seal creates higher pressures both positive and negative. JMHO but I'd do it all at once and get it over with.....2 seals $10-$12....plus you get to clean 23 yrs worth of mung out from behind the flywheel and oil pump/clutch!!!!

 

[taplinhill]

620, might be a 520.

 

[warjohn]

No it may not need it right now but will before long. The 630 Super II in my sig I built from a very worn out carcase a couple yrs ago, did everything except the seals and ran great until this fall but now needs them. Not a big deal but if I had done them when the thing was all apart I wouldn't HAVE to now. I think when you are running a worn out top end the seals are not working with as much pressure and vac as when everything is fresh. That's when these things begin to show up more because good piston fit and ring seal creates higher pressures both positive and negative. JMHO but I'd do it all at once and get it over with.....2 seals $10-$12....plus you get to clean 23 yrs worth of mung out from behind the flywheel and oil pump/clutch!!!!

I have a 670 I am going to start working on this week. It will be my first time changing seals on a saw. Do I need any special tools to remove the clutch or flywheel. Any advice would be appreciated.

 

[Cantdog]

Not really...the clutch comes off with a socket (lefthand of course) I use and automotive bar type steering wheel bar puller on the flywheel. Pretty straight forward. Just remember when you get seals you also get the o-ring that seals the oil pump to the case. (The clutch side seal is actually in the oil pump housing not the case) Good luck..

 

[briantutt]

New (to me) Jonsereds...

Well here it is:

What is it? He scratched "590" into the clutch cover but the fakey picture on acres doesn't show the bottom handle brace going from the rear handle below the rewind and to the front handle...I think every handle on this thing is broke

Guess I'm gonna need an IPL opcorn: