Jonsered 49sp saved ?

[jonsereds 621]

Hello all.
I spend a lot of time on this site looking for info, but don't often post. However, yesterday I was walking down a high street past a skip full of junk and a Johnny 49xp leapt out from under some old plasterboard, scrabbled desperately up the side and shouted for help. When I glanced at it , it said "take me home or I've had it", so I did.
Well it was obviously a non starter. But today it has been a very wet day indeed here. Someone else had had the muffler off, piston has some serious scores and no muffler. But Johnny was in the way, so I took the bar off, 20'' .625...very useable, and gave the clutch a good shifting up & down and back to front.. no play, starter off, same that side. As it happens, I have one of these already, so I know it was good in its day, but now too heavy and awkward.
This one will never be a thing of beauty, or desire. But you know, it's got to run. What has let it down was being run till it stopped with no air filter gauze.
Three questions only really. As it has to be fixed up for as little as possible, and barrel is v good. Would you use a piston again having cleaned it up so no protruding metal (ring groove is good) replace intact old ring ?....or fit the budget'est of budget pistons (£19) ? Has anyone found either a screen from another saw, a filter assembly from another saw, or material to make another screen from, or any alternatives ? Sadly, also it's recoil starter perforated screen is also missing, I am unlikely to find one of those in UK. Other than that.... It appears to be ready to go to work , even has fuel and a good spark.
I notice that the two case halves are not perfectly flush to sit barrell down on, causing base gasket to be cut, or nearly, at front on join. Can I afford a slightly thicker gasket paper, or do I risk slacking off case bolts as I tighten it down, or do I go for a sealant only job (Impulse corridor may become blocked) ?
I am sure some will think I must be insane, but I know there are others here who are worse, and besides, you lot started it !

 

[Cantdog]

Hello all.
I spend a lot of time on this site looking for info, but don't often post. However, yesterday I was walking down a high street past a skip full of junk and a Johnny 49xp leapt out from under some old plasterboard, scrabbled desperately up the side and shouted for help. When I glanced at it , it said "take me home or I've had it", so I did.
Well it was obviously a non starter. But today it has been a very wet day indeed here. Someone else had had the muffler off, piston has some serious scores and no muffler. But Johnny was in the way, so I took the bar off, 20'' .625...very useable, and gave the clutch a good shifting up & down and back to front.. no play, starter off, same that side. As it happens, I have one of these already, so I know it was good in its day, but now too heavy and awkward.
This one will never be a thing of beauty, or desire. But you know, it's got to run. What has let it down was being run till it stopped with no air filter gauze.
Three questions only really. As it has to be fixed up for as little as possible, and barrel is v good. Would you use a piston again having cleaned it up so no protruding metal (ring groove is good) replace intact old ring ?....or fit the budget'est of budget pistons (£19) ? Has anyone found either a screen from another saw, a filter assembly from another saw, or material to make another screen from, or any alternatives ? Sadly, also it's recoil starter perforated screen is also missing, I am unlikely to find one of those in UK. Other than that.... It appears to be ready to go to work , even has fuel and a good spark.
I notice that the two case halves are not perfectly flush to sit barrell down on, causing base gasket to be cut, or nearly, at front on join. Can I afford a slightly thicker gasket paper, or do I risk slacking off case bolts as I tighten it down, or do I go for a sealant only job (Impulse corridor may become blocked) ?
I am sure some will think I must be insane, but I know there are others here who are worse, and besides, you lot started it !

Well I'm probably the resident 49SP guy........and being so... of course my take is to get it going again.....I have way more 49sps than my sig states and find them the best older saws to keep in operation. In recent years VEC has started making fairly nice after market pistons. These saws are certainly not the fastest nor the most powerful......however they are a very good saws.....and are one of the most pleasant saws to run ever!!

 

[sundance]

I'm another 49SP fan, so of course I'd say get it running. Ebay has parts frequently, don't know what shipping to the UK would take.

 

[jonsereds 621]

Well I'm probably the resident 49SP guy........and being so... of course my take is to get it going again.....I have way more 49sps than my sig states and find them the best older saws to keep in operation. In recent years VEC has started making fairly nice after market pistons. These saws are certainly not the fastest nor the most powerful......however they are a very good saws.....and are one of the most pleasant saws to run ever!!

Well...It's all back together looking very promising indeed with it's new VEC piston in a well cleaned up bore and temporary muffler borrowed from a st.... 038. It will start and run fine on tickover, however when I open the throttle gradually nothing much happens. Now I know from my 621's that this indicates blocked high speed jet, however I have taken carb down and removed plugs and cleaned and blown through and am completely satisfied that all is clear and new plug is seated and fuel tight and reassembled. No change, so how about diaphragms, no missing holes that I can see. This saw would tick over for hours if left. I could easily substitute another robbed carb off a runner, but have I overlooked something obvious (or less obvious) because if I have I still won't have an answer and part of the job for me is to overcome all difficulties.
It is easily possible to have this saw ticking over on a wall while opening throttle and adjusting hi and low, but no solution there. Saw is set to full advance at 20 thou point gap with good spark.
So would someone care to lighten my darkness while I make a new screen for air intake.?......Please.

 

[Cantdog]

Well...It's all back together looking very promising indeed with it's new VEC piston in a well cleaned up bore and temporary muffler borrowed from a st.... 038. It will start and run fine on tickover, however when I open the throttle gradually nothing much happens. Now I know from my 621's that this indicates blocked high speed jet, however I have taken carb down and removed plugs and cleaned and blown through and am completely satisfied that all is clear and new plug is seated and fuel tight and reassembled. No change, so how about diaphragms, no missing holes that I can see. This saw would tick over for hours if left. I could easily substitute another robbed carb off a runner, but have I overlooked something obvious (or less obvious) because if I have I still won't have an answer and part of the job for me is to overcome all difficulties.
It is easily possible to have this saw ticking over on a wall while opening throttle and adjusting hi and low, but no solution there. Saw is set to full advance at 20 thou point gap with good spark.
So would someone care to lighten my darkness while I make a new screen for air intake.?......Please.

0.020 is a bit wide.....spec is 0.015...I always set them to 0.016 myself But I doubt that is the trouble. The 49SP carb is the exact same carb as used of your 621 so you could just try a swap to see if that helps. The other thing that come to mind is either the impulse corridor from the case to the cyl may be blocked with sealer....the other thing is did you use the diamond shaped carb to manifold gasket that came with your carb kit? If so it is not big enough to completely cover the impulse passage in the manifold. You can either make a new gasket that is large enough in that areaor if you have a Husky dealer close by you can use the gasket from a 61, 266, 66, 268 or 272. Hope this is helpful...

 

[jonsereds 621]

0.020 is a bit wide.....spec is 0.015...I always set them to 0.016 myself But I doubt that is the trouble. The 49SP carb is the exact same carb as used of your 621 so you could just try a swap to see if that helps. The other thing that come to mind is either the impulse corridor from the case to the cyl may be blocked with sealer....the other thing is did you use the diamond shaped carb to manifold gasket that came with your carb kit? If so it is not big enough to completely cover the impulse passage in the manifold. You can either make a new gasket that is large enough in that areaor if you have a Husky dealer close by you can use the gasket from a 61, 266, 66, 268 or 272. Hope this is helpful...

 

[jonsereds 621]

Thanks for that. Yep, as it happens I have plenty of other carbs the same on good runners, so I could swap easily. However, I feel I should by now be able to identify this problem and put it right. Impulse corridor is not blocked as it lifts fuel from tank and starts easily, I became aware some time after my first tangle with jonsereds 621s that the supplied gasket is not suitable after exhaustive frustrations, it will not happen again! I must simply have something wrong somewhere, but going on how well it will idle indefinitely at whatever position, I am 99.8% certain that problem is carb.
Tomorrow, I will swap for known runner to be certain. I suppose it is possible that metering lever is set too low allowing sufficient fuel for idle, but not for power, however when I open low speed screw further while idling it goes over rich and stops as expected so I am assuming fuel is available, but it is not making it to main jet, but I am able to see its routes is clear. I must say that for the moment at least I am at a bit of a loss, but there will be a solution.
Thanks.

 

[Cantdog]

When you take the carb off, pull the "H" needle and take a can of WD40 with the supplied red straw and holding the throttle plate open and the choke open so you can watch the carb bore, insert the straw into the "H" jet and give it a squirt...the WD should come out of the main orifice into the carb bore in a good stream. Just an easy way to check the interior passages are in fact clear. Same thing can be done with the "L" jet check the idle circuit and it's two orifices. Occasionally you will run across a carb that no amount of fussing will seem to remedy.

 

[jonsereds 621]

Well now, I should have dropped to this earlier, but I just couldn't see it. Swapped carbs with a 49sp saw in use, still no good but carb from troubled saw works fine straight off on donor. At which point I realise that I have used a lot of fuel in 20mins or so tickover and adjustments, as fuel in tank is finally consumed it begins to run normally, then goes toward overspeed. stop switch is in top on floor, but thankfully cable end is free on top of handle. Tank is leaking into crankcase causing inability to two stroke with throttle open, but is fine on tickover. It did not leak down on previous pressure only test (no vac), but pressurise tank and bingo, got it.
So it has to come apart. Before I start in 7-10 days, what am I going to miss bolt wise on separation, at a glance, they all come out from flywheel side. While I am at it, I may well decide to replace crank bearings. is there a suitable replacement freely available, or is it n.o.s only ? From memory only, bearings are going to be open, nylon cage deep groove,i wonder if they are the same on a 621 ? I have 241753 skf as original part, perhaps 15x32x9, although this sounds unlikely ?? It is never going to be a looker dolly, but if I go to the trouble, I want a pleasant useable saw cheap. If not, piston will go to other 49sp. On close inspection of gasket visible through filler, it looks like a replacement, on the thick side. Just as visual of it disappears from view toward bottom I can see complete change of colour and it dodges in toward crank.....Tank vent is clear and working.
ANY other tips ? links would be much appreciated . If I can get it to part without damage, I can certainly put it back together.
Thanks in anticipation.

 

[Cantdog]

Well that's to bad. I did a thread a few yrs. back on this site entitled "49SP and 70E Build From Scratch"....search the title....you might find this helpful. However this was pic heavy and when this site got hacked and nearly destroyed all the pics were lost, making the thread almost useless. It was meant to be more or less of a tutorial on how to fully disassemble, rebuild and reassemble these older saws. It actually became a three saw build mid way through, building 2 sp's and one 70E. I have all the pics and they are numbered in the thread so if you want any of these in particular just ask for the numbers and I can post them here for you. The stock main bearings are generally SKF 6002/C3 bearings available at any bearing supply or auto parts stores. If my memory is correct the 621 has slightly larger bearings 6202/C3 I believe same as the 70E and the 80/90.

Here is a pic of the crank seals I used......the TCM # is the size of the ID, OD and thickness in MM that order.....OEM seals were 6 MM thick and these are 7 MM thick but has never been a problem. Remember to get double lipped seals as they must hold pressure and vac.

 

[jonsereds 621]

Thanks for the extremely valuable information. As it happens, I am away from home right now and will be in a favourite bearing factor's place at 4pm today, looking for bearings and seals for a large hydraulic pump, that comes apart in a broadly similar way, although there are FAR more parts inside !
I look for your post and go through it most carefully while digesting your process.
I will most likely be back for further info, but for now I have all I need.
Thanks again.

 

[Cantdog]

Feel free to ask for any pics or other help that I may be able supply. Good luck..

In what part of West Wales do you live??

 

[jonsereds 621]

Well thanks for that. As I'm not yet into the job but will be, I can only ask questions that come into my mind, answers to which may or may not become apparent on the job as it were.
Firstly though, I live in south west Wales, about 21 miles west of Carmarthen, midway between St clears and Narberth. My first saw was a 621 new in about 1984 perhaps, it is still in use here almost weekly. At the time I was farming in Worcestershire , we had about 140 very large dead Elm trees, some 50ins dia. and my neighbour was the only person I new with a chainsaw which was a 62. He was bored with hitting horseshoes and grown in fence wire so would only cut them off to leave a 5ft high stump. I knew better at 22yr old, so the view was "better get your own then". I asked him what would be a good choice and answer was ..go and see Chris, he's just got a new 621, next one on from this. so I did, and spent the morning attacking a very large fallen elm which was like iron with a new 621. After that there was only one way to go. since this time I have aquired five more 621's one of which I would say had only done 30mins work along with various other plastic saws which certainly have their advantages. I burnt one 621 accidentally, along with fuel, oil, tools my jacket and a new packet of cigs late at night, by putting the lot into loader bucket before I knocked off and went home. decided to stop and admire fire with a fag, last in that pack. by the time I had done that fire needed rounding up and girlfriend had arrived, so I pushed it up again and went home.
I didn't realise the significance of the strange glare from distant fire as I got off to open a gate until I needed that packet of fags after ( 'supper' ).
So somehow now I feel that I owe them.
A few small questions spring to mind, I have cut two arms for a case splitter as per template from DEPRIME on this site, but can see no dimensions regarding distance apart so have not proceeded further.
Am I pulling case and bearing, or case only, it would seem logical to pull on bearing only, removing case and bearing together.
I don't see what will centre crank in case, thought there would be a shoulder, either for one or both for centralisation. I don't see it in exp diagram I have.
More to come. Action ! Thanks.

 

[Cantdog]

Well thanks for that. As I'm not yet into the job but will be, I can only ask questions that come into my mind, answers to which may or may not become apparent on the job as it were.
Firstly though, I live in south west Wales, about 21 miles west of Carmarthen, midway between St clears and Narberth. My first saw was a 621 new in about 1984 perhaps, it is still in use here almost weekly. At the time I was farming in Worcestershire , we had about 140 very large dead Elm trees, some 50ins dia. and my neighbour was the only person I new with a chainsaw which was a 62. He was bored with hitting horseshoes and grown in fence wire so would only cut them off to leave a 5ft high stump. I knew better at 22yr old, so the view was "better get your own then". I asked him what would be a good choice and answer was ..go and see Chris, he's just got a new 621, next one on from this. so I did, and spent the morning attacking a very large fallen elm which was like iron with a new 621. After that there was only one way to go. since this time I have aquired five more 621's one of which I would say had only done 30mins work along with various other plastic saws which certainly have their advantages. I burnt one 621 accidentally, along with fuel, oil, tools my jacket and a new packet of cigs late at night, by putting the lot into loader bucket before I knocked off and went home. decided to stop and admire fire with a fag, last in that pack. by the time I had done that fire needed rounding up and girlfriend had arrived, so I pushed it up again and went home.
I didn't realise the significance of the strange glare from distant fire as I got off to open a gate until I needed that packet of fags after ( 'supper' ).
So somehow now I feel that I owe them.
A few small questions spring to mind, I have cut two arms for a case splitter as per template from DEPRIME on this site, but can see no dimensions regarding distance apart so have not proceeded further.
Am I pulling case and bearing, or case only, it would seem logical to pull on bearing only, removing case and bearing together.
I don't see what will centre crank in case, thought there would be a shoulder, either for one or both for centralisation. I don't see it in exp diagram I have.
More to come. Action ! Thanks.

That's Beautiful country.....A couple yrs back we came into Holyhead/Anglesey from Ireland, then went up to Conwy then down through Snowdonia and then on down through Brecon Beacons to Cardiff......doing the tourist thing....but ...well we were tourists!! LOL!! Gotta have Brains!!!! LOL!!

The 621 is an awesome saw.....I wanted one badly in 1977 when I bought my new 49SP but didn't have the funds. A number of years went by and one night I was sitting in a local pub chatting with some friends and the conversation got around to chainsaws and then to Jonsereds in particular.....I stated that I had always wanted a 621....a guy laughed and said "I have two you can have" and a couple days later he showed up at my shop with two broken 621s....one was very used and the other with lees hours but broken parts galore. I thanked him, looked them over and decided that the two would make one good one......someday......I slid them under a bench where they proceeded to collect dust for a few more years...a lot of dust... as it's a wood shop. I moved out of that shop in 2002 and almost threw them away but couldn't quite bring myself to. I had not started my chainsaw thing at that time.....I needed chainsaws and I used them and took care of them like any other tool. So they languished under the new bench in the new shop along with my old completely worn out 49sp for a few more years. We had a serious economic turn down in 2008 and I went from a backlog of three years work ahead to nearly nothing at all. So in my boredom one day I dragged the two 621s out from under the bench and in 4 1/2 hours I was cutting wood with a real sweet running/looking 621......and as they say.... the rest is history.....I got to looking online for parts, ended up here and now I have WAY to many Jonsereds!!!! Many more than my sig as it won't let me add any more saws to it. Love them all, each and every one but the 621s and 49SPs are still my favorites!!!

 

[Cantdog]

Well thanks for that. As I'm not yet into the job but will be, I can only ask questions that come into my mind, answers to which may or may not become apparent on the job as it were.
Firstly though, I live in south west Wales, about 21 miles west of Carmarthen, midway between St clears and Narberth. My first saw was a 621 new in about 1984 perhaps, it is still in use here almost weekly. At the time I was farming in Worcestershire , we had about 140 very large dead Elm trees, some 50ins dia. and my neighbour was the only person I new with a chainsaw which was a 62. He was bored with hitting horseshoes and grown in fence wire so would only cut them off to leave a 5ft high stump. I knew better at 22yr old, so the view was "better get your own then". I asked him what would be a good choice and answer was ..go and see Chris, he's just got a new 621, next one on from this. so I did, and spent the morning attacking a very large fallen elm which was like iron with a new 621. After that there was only one way to go. since this time I have aquired five more 621's one of which I would say had only done 30mins work along with various other plastic saws which certainly have their advantages. I burnt one 621 accidentally, along with fuel, oil, tools my jacket and a new packet of cigs late at night, by putting the lot into loader bucket before I knocked off and went home. decided to stop and admire fire with a fag, last in that pack. by the time I had done that fire needed rounding up and girlfriend had arrived, so I pushed it up again and went home.
I didn't realise the significance of the strange glare from distant fire as I got off to open a gate until I needed that packet of fags after ( 'supper' ).
So somehow now I feel that I owe them.
A few small questions spring to mind, I have cut two arms for a case splitter as per template from DEPRIME on this site, but can see no dimensions regarding distance apart so have not proceeded further.
Am I pulling case and bearing, or case only, it would seem logical to pull on bearing only, removing case and bearing together.
I don't see what will centre crank in case, thought there would be a shoulder, either for one or both for centralisation. I don't see it in exp diagram I have.
More to come. Action ! Thanks.

You should have the "Fingers" of the case splitter close enough together that then hold the inside of the bearing outer race......this way the bearing stays in the case when you push the crankshaft out. Then with the case half laying flat on the bench you can drift the bearing out......this is much easier than pulling the bearings off the crank once it's out. Here are a couple pics from that thread showing my "store bought" Husqvarna splitter.....it works OK on the 49s smaller bearings but is to wide so I ended up making a "U" shaped pad to slip in to catch the bearing race and rest the "Fingers" against....it works great on the 621 and up saws without the pad. If the bearing comes out with the crank then you have to resort to suing a puller like in the second pic....they come off pretty hard as you also have the bring the oil pump drive gear with the PTO side bearing.

 

[Cantdog]

There are shoulders in the cases that keeps the bearings from moving to far outboard in either direction......

 

[jonsereds 621]

Hi there, my you certainly went to some trouble with the photo's. Excellent work, truly excellent. I can see perfectly what I am aiming at from those....should be little trouble. I have bearings and seals. However, I also received a lecture (from a friend)on the "double lipped seal" I had in my hand.
Interesting to only a few. the original seal from a jonsered 621 I am informed is indeed a double lip, however it is described accurately as double lipped, single seal c/w single garter spring, and a contact type dust skirt, the same seal also described as double lipped is also available with etc, and non contact type dust skirt, I went for contact type while I was there although I have perhaps a dozen already. a double lipped, double seal in that size with twin garter springs requires more width, when its already tight, quite a lot more. Also about six times the price. I am unable to find dictomatik 15x30x7tc-bx in the uk, but as it's x7, perhaps its actually a single seal with contact dust skirt. (cheap enough equivalents).
His parting shot as I left was "I hope you are not fitting those for Harry" Harry is in liquid egg production, worked with him today, received another lecture. Also wanted to know if he had just paid for them.
Your photos really are excellent, my congratulations. I have only ever felt that pipe in oil tank, I can't believe its only poss to replace from inside ! chances of finding something as good to replace it with are slim indeed.
I will let you know how I get on. Thanks again.

 

[jonsereds 621]

Hello there again. Successfully split case and bearings from crank with no casualties. With my splitter, I added a thru piece of thread bar and four nuts into the fingers around 1 1/2 ins from weld to box spine (just on from internal curve start) mainly to control distortion as I welded it together. Works a treat to adjust finger separation distance, giving it a most useful range for other jobs (two already) . How are you managing to make such a smart job of cleaning off old hard case gasket ? Face plate and glued down glass paper ? nearest I can get here is glass and glass paper. Wife is away, her top oven in Aga sits nicely at 209 f right now and will go higher with more kero, but will then be too hot for my dinner. Await instructions !....... Dishwasher cleans case halves perfectly while asleep, even better with the stuff to make glasses sparkle. Got a good feeling about this saw already.

 

[Cantdog]

Did the bearings stay in the case halves or come out with the crankshaft?

 

[jonsereds 621]

The bearings come out with case, tapped gently out of case without difficulty. My aim (when old gasket is clear) is to reassemble in reverse order, as per your system. either then heat case, or case splitter with tubular adapter could be used (mine I inch longer stroke for other purposes) to push on surface where oil seal will seat into. I can see that oil pump drive would prob break up given rough treatment, so heat excellent solution to get this back on crank.
I removed oil pump and driven gear before disasembly, but is this really necessary for no2 49sp ? I suppose there would be no way to tell if meshing or otherwise....... !