Jonsered 49sp saved ?

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Idiot ?

  • Yes indeed.

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Yes I always take the oil pump out when assembling or disassembling just one less thing to have to fiddle with when you're trying to get the case halves back together before they cool to much. I prefer heat to pulling the bearing into the case cold....once things are the correct temp they just fall into place....if it's a struggle then the temp isn't high enough. Back they go for a little bit. I scraped very carefully the gasket surfaces then with a piece of wet/dri 400 grit on my table saws top to bring up the aluminum to a nice even. bright finish.....a piece of thick glass would work fine as well. Again....if you need/want any of the pics posted from the thread just tell me what numbers you want to see and I post them up as quick as possible.
 
Very simple question? I have never seemed to be able to get my blue hylomar on to jobs like this thin/even enough for my liking, I see it seems to be your favourite as well, any good tips for this ?.....or does it allways turn into a digit job. I have a fresh tube in the warm. I may seem to have turned this saw into a long job, but as I have a number of similar saws I felt while I was at it I would make the tools to do it easily while I was at it, thus widening somewhat any future prospective candidates. It seems I will need my own dishwasher machine first though as I am told that scrambled eggs ''taste different"...
Any one else considering this job should be able to reproduce required case gasket etc from attached.
 

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  • Jonsereds 49sp crankcase gasket.pdf
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No......it is always a finger job for me as well....no tricks that I know of. The amount of resistance when pulling my finger across the "wetted" surface of the gasket tells me how thick the application is....if the finger drags to hard there is not enough....if it slides to easy there is to much.....

Sounds like you're coming along on this project...it takes a while to come up with the right tooling for these saws....some can be purchased, some are best home built which may well have to be of your own invention.

This is a very simple puller I made. This will pull the flywheels and clutch spyders on the 49sp, 52/52E, 621, 66/70E, 80 and 90 using various appropriate length bolts.

Saw Tools 010.jpg
 
Yes indeed, I have a puller that does these jobs. I don't think its my imagination, I will double check again, but I found with this particular 49 the clutch Spyder required not only a diff length bolt as usual, but also a very slightly smaller diameter bolt- still the same thread..... these also fit the 621 clutches, but not the flywheels. I have a feeling that my puller came with my first 621 (which I still have, going well) along with a small grease gun , an excellent aluminium angle file holder -gage, now worn out and various other spares , now consumed long ago. The puller is very advanced, in so much as it also has a rather coarse threaded bolt with a square head in the centre to do the pulling. The only thing I had at the time that fitted this was an adjustable spanner (metric spanners had not yet become necessary in my small array of tools. All AF.. It wasn't long before I was the only person for miles with a full set of metric Allen keys however. This sort of behaviour was viewed at the time in my local agricultural community as........conspicuous expenditure !
It was about the same time that I aquired another 621 as a non runner at auction as a result of having to borrow a much older saw, I think danarm , which wouldn't start, but when it did it raced with nothing much in between to free my severely pinched 621 from the base of a wire filled very shaky dead elm overhanging a busy road. This saw was blessed with a pump oiler which wasn't handy in so much as you had to get off the throttle to reach pump at which point it would stop.... luckily it all ended well. I realised there and then that I had a proper saw, and here we are for the first time needing to get right inside one.
Speaks for itself I'd say. All made a whole lot easier with all the information I could possibly need available after a few short lines typed onto a screen that does not have to warm up, and the first response coming from the most north eastern part of America. Staggering if you pause to think about it.
I am rather savouring the reassembly. Other points so far. Endorsing ink for copying case gasket to paper, does not dry out so fast, intended for old style adjustable belt type date stamps, far better than Marmite or biro ink. E'bay. Ha! .
Strange the way Hylomar won't come off your fingers, until you make a cheque out, or help the wife fold some sheets though, don't you think !
 
HaHaHa......you're right about the Hy-Lomar!!!! And also correct how easy it is to gather information on a subject these days. Seems like anything I am having trouble with someone else has already had the same problem before and somewhere on the web it has been thoroughly discussed and a solution generally available!!!

Enjoy your rebuild of the 49SP...a very friendly saw to have and use. Keep us posted on your progress!!!
 
Johnny LIVES ! All back together, fresh 'own design' carb intake screen, crank bearings, seals and VEC piston, now completed and running with borrowed chain and bar 3/8 x 16'' and will tick over easy with quick translation to power on. The difference new bearings and seals and also its rim drive clutch make to produce a real quality feel to this saw has to be experienced to be believable. Rolls Royce springs to mind, but bearing in mind any likely reader of this, perhaps "Cadillac" will be more suitable !
I heated bearings and pump drive in oven to fit as suggested and this went very easily, however I did not fancy a magnesium fire in my wife's cooker while she was away so manufactured a simple puller from m16 threaded bar, it has an m10x1 Rh and m10x1 Lh adapters to screw on the end of the m16 bar and a piece of tube which fits over adapter c/w detachable bush to case on to bearings. This, with a smear of copper slip allowed crank and bearing to be drawn into case without any difficulty whatever, it also allowed for a very controlled fitting of flywheel side alignment and descent to touchdown. I also used it to centre crank. It would seat the seals also, but I just used one bush and tube to put them in flush.
All in all , I found this job extreemly satisfying and inexpensive, and have ended up with a quality saw for very little cash indeed. I would suggest to anyone else that this may rather simpler than they expect, particularly if you have a lathe, however attention to detail will pay off in future. My longer term results remain to be discovered, however , it is going to work in an overgrown blackthorn hedge this afternoon, which should provide a good deal of varied throttle openings and tick over periods. I expect it to complete its first fill or two with no further adjustment.
Particular thanks to Cantdog for info and fabulous photo's supplied which provided invaluable insight as to what was in front.
 
Congrats!!! These are very nice, solid feeling saws...not quite as fast as some of the more modern ones but work very well none the less.

Here is a pic of the used electric toaster oven I use to heat the cases.....I have run case halves up to 275 degrees F with no paint or metal damage what so ever.
Picked this up at a yard sale for a couple dollars....Cheap enough to insure that the world of the shop never encounters the world of the kitchen!!......works great and with the clear front I can monitor the temp with a digital laser thermometer.

49 SP and 70E Build 027.jpg
 
Congrats!!! These are very nice, solid feeling saws...not quite as fast as some of the more modern ones but work very well none the less.

Here is a pic of the used electric toaster oven I use to heat the cases.....I have run case halves up to 275 degrees F with no paint or metal damage what so ever.
Picked this up at a yard sale for a couple dollars....Cheap enough to insure that the world of the shop never encounters the world of the kitchen!!......works great and with the clear front I can monitor the temp with a digital laser thermometer.

View attachment 633882
And cook instant meals whenever hungry!!!
Great work Robin as always!!!
 
This is sort of an update as to how things are going along. The difference between my two 49sp's is very marked indeed, this latest one c/w new piston & bearings and my other is the difference between a venerable old saw and a tool I might select for the job even with much more modern alternatives. As a result, it has had now a fair bit of work since. Perhaps eight -ten tank fulls. However, I now have a problem that I see is not that unusual. It will not restart when hot. I am certain it is not carb/fuel related, and it is not points or condenser, as I get same prob after temporary fitting of transistorised ignition, which perhaps runs smoother, but without doubt gives less power. So, swap coil for known runner and all ok. This is in itself not a problem, as I cannot use two, but having found myself unable to reproduce to anything like a presentable recoil intake screen which did not rip my trousers etc whilst carrying.......I was forced....FORCED mind you.. to purchase another 49sp as for parts only, none runner. Naturally, it is in marginally better cosmetic shape than than this one whose performance I would now describe as very strong indeed for what it is, and had a very good recoil assy. Its coil produces no spark at all, hot or cold!
I have read somewhere here that the coil for a Pioneer p28,p26,or p1074 will do the job, and also perhaps Homelite super xl. From what I can see, the modern offerings of these are coil modules, (incorporating transistorised ignition?) which from my very limited experience so far also advances\retards spark presumably to make starting easier, but in these cases at least do not help with performance.
Before I embark on a do yourself exploratory coil examination / rewind / frustration exercise (I understand that there may be some thousands of turns) I want to ask if anyone has a 49sp running on points, but with a coil from something else, preferably available without difficulty.

I do have a no name Chinese chainsaw, also aquired free, which starts and runs well with its butchered stihl 025 coil (module) which had mounting holes in wrong places, but didn't after I had " personalised " it.
Any constructive thoughts on this before Britain starves from loss of agricultural output due to unnecessary diversion of labour. I now need at least two.....probably three, oh, and a spare.
 
I do not know of a replacement coil.....that said I see no reason one could not be adapted as long as it fit's under the recoil cover and positioned to correctly time the saw.
This is why in my sig it states "Many 49sp parts saws".....every saw carcass, no matter how picked over looking can produce some much needed parts!!!
A couple observations/comments/questions. You can try to reduce the air gap on the original coil to get better spark. There was a service bulletin for the late model 70E which used a very similar coil to the 49sp to enable easier starting. The stock air gap is 0.012"...they suggested reducing that to 0.007" for easier starting. Also, on these saws it is important that your fuel tank vent is loose and working properly as since the fuel tank is part of the engine case it gets quite hot...hot enough to boil the fuel when shut off...it the vent is sticking this will over pressure the carb with fuel and flood the engine whilst just sitting there hot.
I assume you tried the coil from your latest parts saw on your rebuilt saw to check for spark rather than just testing on the parts saw as the points may be oxidized on the parts saw and not allowing spark.
 
I do not know of a replacement coil.....that said I see no reason one could not be adapted as long as it fit's under the recoil cover and positioned to correctly time the saw.
This is why in my sig it states "Many 49sp parts saws".....every saw carcass, no matter how picked over looking can produce some much needed parts!!!
A couple observations/comments/questions. You can try to reduce the air gap on the original coil to get better spark. There was a service bulletin for the late model 70E which used a very similar coil to the 49sp to enable easier starting. The stock air gap is 0.012"...they suggested reducing that to 0.007" for easier starting. Also, on these saws it is important that your fuel tank vent is loose and working properly as since the fuel tank is part of the engine case it gets quite hot...hot enough to boil the fuel when shut off...it the vent is sticking this will over pressure the carb with fuel and flood the engine whilst just sitting there hot.
I assume you tried the coil from your latest parts saw on your rebuilt saw to check for spark rather than just testing on the parts saw as the points may be oxidized on the parts saw and not allowing spark.
Yes, indeed. I tried latest parts saw coil on rebuilt saw, no go, and then on runner and no go (at 12 thou). I put runners coil on rebuilt saw at 12 thou and started right away. However, today I received a spark tester with an adjustable gap (old style) but have not yet tried on any saws, but shows good spark at 8mm gap on old log splitter motor, which started right away on reconnection. I had not thought to try reducing gap on either running 49sp, or rebuilt saw at .007 however. Tank vent is definitely clear, saw is not flooding and no change with vent removed \tank open. Little time spent on it today as I have a few sheep lambing inside, very poor conditions/ cold and wet outside and one ewe with a treble, big tits which her small lambs cannot figure out...yet.
It is most fortunate that 49sp coils are very easy to get at, although perhaps less easy to find to find a replacement for. I shall be very surprised indeed if I am not able to find a cheap easily adapted and freely available coil (although most likely module) which will be smaller no doubt within a month, perhaps less.
Britain has recently had what it thinks is some cold weather for 3-4 days here -1c day and -4-5c night- windy, snow. No doubt you often manage to keep going in far worse conditions, what is a cold period where you are and do you keep studded w tyres, and plug cars in overnight as in Norway and keep a plastic or ally shovel for paths and doorways etc, or is it always a big surprise there too with burst pipes and trains at a stand still, bust cars and closed airports? Thanks for suggestion for less air gap, will give it a shot later.
 
No... here we are very used to winter....the last couple week of Dec. through the first week in Jan. we were around zero F during the day and minus 10-15 F below every night...I drive a Four wheel drive truck with studded snow ties all the way around. Years back I used to drive Land Rovers...Series II, IIA and IIIs.....I still have four non running ones....the frames don't like it here....they put to much salt on the roads. And yes every auto has a shovel in it about 6 months out of the year. I also have a couple 521E Jonsereds with hi/low electrically heated handles.....very nice when cold!!!!
 
No... here we are very used to winter....the last couple week of Dec. through the first week in Jan. we were around zero F during the day and minus 10-15 F below every night...I drive a Four wheel drive truck with studded snow ties all the way around. Years back I used to drive Land Rovers...Series II, IIA and IIIs.....I still have four non running ones....the frames don't like it here....they put to much salt on the roads. And yes every auto has a shovel in it about 6 months out of the year. I also have a couple 521E Jonsereds with hi/low electrically heated handles.....very nice when cold!!!!
Well...DAMNATION......At 7 thou plus 1 smidgen I get a real fat spark from both,(running on points ) how about that then. I don't know why, but I would never have dropped to that. I have yet to see if it will restart from real hot (coil uppermost for refuelling) but it looks most promising and runs fine.

So.. as they say... "May the fleas from a thousand Camels infest your enemies"

Mind you, if they can tolerate the starter motor securing bolts location on a series 3 or was it 2, up there, I would imagine fleas would not bother them in the least !
It completely defeats me as to why someone would select that vehicle for a trip across a desert or other dangerous place, let alone to do the shopping. Most of them would not be able to get it into FWD......Mind you I also have long legs.
It sounds to me as though you are well prepared for slippy snowy roads etc, I don't understand why, but it is always a surprise that it might get cold and snow here in the winter, doubt I could find a car or truck with a shovel in the back for 150 miles here. I keep chains, but still no shovel on board..
I shall continue my search for an alternative coil nonetheless.
Thanks again.
 
Glad that seemed to work for you....I have never tried it but as I said it was a service bulletin for the late model 70E. Next time I have spark issues I'll give it a shot!!

Well the Rovers were built to repair and were very heavy duty in their weight class vehicle....not that pleasant to use on the road.....I always said that Rovers were four wheel drive off road vehicles with 2 wheel drive, on road capability......whereas Jeeps were a 2 wheel drive road vehicle with four wheel drive off road capability....

On the subject of snow I saw Ireland has had a lot of snow for them!!! Also, though were have bare ground presently....we are forecast to acquire 12-16" of new snow in the next couple days.....and I was hoping for an early spring....
 
Glad that seemed to work for you....I have never tried it but as I said it was a service bulletin for the late model 70E. Next time I have spark issues I'll give it a shot!!

Well the Rovers were built to repair and were very heavy duty in their weight class vehicle....not that pleasant to use on the road.....I always said that Rovers were four wheel drive off road vehicles with 2 wheel drive, on road capability......whereas Jeeps were a 2 wheel drive road vehicle with four wheel drive off road capability....

On the subject of snow I saw Ireland has had a lot of snow for them!!! Also, though were have bare ground presently....we are forecast to acquire 12-16" of new snow in the next couple days.....and I was hoping for an early spring....

Well this saw has turned into a firm favourite with me, now is fully reliable and eager to go, and from a user point of view in light work will cut at less than full throttle without stalling chain,so no frantic screaming to trim off small side shoots etc. ideal in its current task of hedge laying /redesignation of tree to hedge bottom. Only drawback against it here is that obviously it still pumps oil while ticking over in between, but motor doesn't just stop when I pick it up.
It is now a great pleasure to use, almost a privilege. I can quite see now why these are a favourite.
Only snag to this latest saga is that the saw bought to provide starter intake screen, on closer examination seems to have an as new bore with a lot of soot, and an as new piston with a broken ring. It must have run a bit like this to produce the soot, but no damage to speak of. New ring arrived from Greece yesterday, so now I need (maybe) another recoil screen as before. It also looks as though it may have been apart as barrel hold down bolts had locktite or similar, seals appear to have been replaced rather inexpertly with some red sealer around. Where does this all stop, or is there... No obvious limit. I already had one when I walked past that skip, now that one from the skip is better. Original will get the same treatment, difficult to see how it could be better still. but.. Now there could be a third. I can only use 1or 2 saws in a day surely ? But, it would make sense to use the gear I now have for more than one or two wouldn't it ? Thanks for the most valuable info.....I am not able to keep my workshop up to your most enviable standard of tidyness. Congrats.
 
And so it begins....you have now progressed to the stage of buying of parts saws for your parts saws!!! LOL!!! But the 49SP is a very worthy saw to become afflicted by...but you have to take that opinion from where it came...!!! The only saw I ever bought new...back in 1978....still one of my go-to saws!!!
 
And so it begins....you have now progressed to the stage of buying of parts saws for your parts saws!!! LOL!!! But the 49SP is a very worthy saw to become afflicted by...but you have to take that opinion from where it came...!!! The only saw I ever bought new...back in 1978....still one of my go-to saws!!!
Would you be able to post a photo of your method of supporting piston for installation of barrel without fouling up gasket and sealer on the way ?
Sounds simple enough, but I have not managed to replicate it yet, and this bit needs to be right, also, its about to happen again........and again.
I'm telling you, you just can't beat a piece of refined two stroke growl and perfection in an isolated spot by a fast flowing stream on a warm afternoon, while working on blown green ash........Almost for free !
 
Sure........These are pics of the 70 E but the 49 done exactly the same way. The first part is done with the sealer on the gasket bottom and the case the blocks of wood hold it in place, then after the ring is in the bore and a zip tie cut free you can coat the top of the gasket. I usually assemble without sealer if using home cut gaskets and when using the NOS thin paper gaskets I let them sit between two pieces of dampened paper towels for a half hour or so to make them flexible. I don't use sealer except when having to reuse a gasket or when eliminating the gasket to gain compression. I really don't bother eliminating the gaskets on these old saws as the original thin paper gaskets, when under compression from the cyl bolts is reduced to around 0.007" so there is not much to gain there.

49 SP and 70E Build 092.jpg 49 SP and 70E Build 093.jpg 49 SP and 70E Build 095.jpg 49 SP and 70E Build 096.jpg
 
Sure........These are pics of the 70 E but the 49 done exactly the same way. The first part is done with the sealer on the gasket bottom and the case the blocks of wood hold it in place, then after the ring is in the bore and a zip tie cut free you can coat the top of the gasket. I usually assemble without sealer if using home cut gaskets and when using the NOS thin paper gaskets I let them sit between two pieces of dampened paper towels for a half hour or so to make them flexible. I don't use sealer except when having to reuse a gasket or when eliminating the gasket to gain compression. I really don't bother eliminating the gaskets on these old saws as the original thin paper gaskets, when under compression from the cyl bolts is reduced to around 0.007" so there is not much to gain there.

View attachment 639547 View attachment 639548 View attachment 639549 View attachment 639550
I see. I think my problem is simply a difference of method going back a long way. The first gaskets I ever made were cut from breakfast cereal packets. years ago, I reckon the quality of this cardboard was a lot better, some premium cereals were sold in cardboard packs that had a shine to them, and made gaskets that held up better. Later, various gasket goos came freely available, and I tried various of them, always coating cut gasket first, and allowing to soak in well before fitting, finally I settled on blue hylomar, probably 30 yrs ago, mainly because it worked really well on radiator hose connections that were prone to leaking, and difficult to get at again later......and never hardened or bonded. well, I still use only that, and I still coat both sides of new gasket, and allow to dry...perhaps 5 mins. added benefit is this gasket will almost certainly be reusable next time as sealer penetrates into it to an extent, rather than producing a sticky mess all around, that probably you can't get to to clean off and indicates to any future inspection that it has been dismantled.
It had not occurred to me that I might try (now equipped with "proper" gasket material) fitting dry. As this is already a good fit, and now I can simply cut another from pre printed out sheet, and if that is lost, or empty, simply refer to my pc's new gasket library and print another sheet ! Also, by some comparisons, this is a cynch to get at. This would allow two wood strips as you show to be used easily, greatly easing an already straightforward if fiddly job.
Great strides I'd say !! As usual, the answer lies in the detail. Thanks for that. Jim.
 
I see. I think my problem is simply a difference of method going back a long way. The first gaskets I ever made were cut from breakfast cereal packets. years ago, I reckon the quality of this cardboard was a lot better, some premium cereals were sold in cardboard packs that had a shine to them, and made gaskets that held up better. Later, various gasket goos came freely available, and I tried various of them, always coating cut gasket first, and allowing to soak in well before fitting, finally I settled on blue hylomar, probably 30 yrs ago, mainly because it worked really well on radiator hose connections that were prone to leaking, and difficult to get at again later......and never hardened or bonded. well, I still use only that, and I still coat both sides of new gasket, and allow to dry...perhaps 5 mins. added benefit is this gasket will almost certainly be reusable next time as sealer penetrates into it to an extent, rather than producing a sticky mess all around, that probably you can't get to to clean off and indicates to any future inspection that it has been dismantled.
It had not occurred to me that I might try (now equipped with "proper" gasket material) fitting dry. As this is already a good fit, and now I can simply cut another from pre printed out sheet, and if that is lost, or empty, simply refer to my pc's new gasket library and print another sheet ! Also, by some comparisons, this is a cynch to get at. This would allow two wood strips as you show to be used easily, greatly easing an already straightforward if fiddly job.
Great strides I'd say !! As usual, the answer lies in the detail. Thanks for that. Jim.

You are very welcome. Glad that thread is still being useful. Happy to post pics as desired. It was veryt disheartening when all the pics were lost to the general public. I started using HyloMar probably 20 years ago and it is just about the only sealer I use. No petrol based chemicals touch it.....and as you stated you take the joint apart and simply add a very small amount if any and reassemble.....no scraping or fussing. Well worth the price IMHO. I use it exclusively on petrol tank sending units below decks on vessels where ANY petrol leaks can spell disaster!! They never leak a drop and everything comes apart easily for inspection or tank cleaning. Good Stuff!!!

As usual there many ways to an end....but I find the blocks of wood cut to hold the piston at or very nearly TDC works best for me......and I prefer the zip tie ring compressor over the store bought ones you have to pinch with one hand while wiggling the cyl on with the other. This method leaves both hands free to work the cyl onto the stationary piston with completely predictable results. You may have also noticed in the one pic I show the ring locating pin clearly visible (and in the correct position) through the space where the zip tie joins itself.
 

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