49sp Jonsereds chainsaw

[andydodgegeek]

Grandpas 49sp

When I was a kid my grandpa lived about 1/3 of a mile away and I hung out with him alot. I remember helping him when he was cutting wood and he had a homelite saw. One day me and my dad were helping him and I dont remember exactly what happened but his homelite got crushed by a tree. I mean crushed, we cleaned it up with a rake. He replaced it with a Jonsereds 49sp. He used that saw alot until his health went bad and then he passed. He was a wood cutter into his 80's. When he passed my dad got his 49sp and about a year ago I got it. I cleaned it up good and got it running good. I dont use it often because I have my "go to saws" but I enjoy bringing out grandpas saw when I am grilling and need to cut up some smoking wood. I am sure my grandpa would like to see his saw looking all nice and clean, and I think he would enjoy a piece of smoked chicken. I will take some pics of it tommorrow and post them.

 

[keychange]

The crank seals can be had at any industrial bearing/seals place. You need a Double Lipped seal 35MM (OD) X 15MM (ID) by 7mm thick seal. There are some seals that are better than OEM...buy the best you can get..expect to pay $7-$8 each

I have had mine since new in 78 and it has been a great workhorse for firewood on tough Australian hardwoods. However recently had some problems with over-heating and dying so I have put a new carbie kit and plug but I can't get it to idle - the low speed jet appears so touchy... then it occurred to me that it could be the crank seals - any thoughts?

 

[PB]

I have had mine since new in 78 and it has been a great workhorse for firewood on tough Australian hardwoods. However recently had some problems with over-heating and dying so I have put a new carbie kit and plug but I can't get it to idle - the low speed jet appears so touchy... then it occurred to me that it could be the crank seals - any thoughts?

It could be, but it could also be the fuel line. Have you replaced the line recently, if not you should start there.

 

[Cantdog]

I have had mine since new in 78 and it has been a great workhorse for firewood on tough Australian hardwoods. However recently had some problems with over-heating and dying so I have put a new carbie kit and plug but I can't get it to idle - the low speed jet appears so touchy... then it occurred to me that it could be the crank seals - any thoughts?

Welcome to the site keychange. It is probably time for crank seals anyway...you can only expect to get 34-35 yrs out of a rubber seal, especially in a hot climate. If you have already put a carb kit in did you use the gasket that came in the kit between the carb and the manifold/isolation block? These gaskets do not work on these saws as they are not large enough to cover the impulse corridor. You will either need to reuse the old one (if intact) , make a new one or go to your local Husqvarna dealer and ask for this gasket to fit a 61,66,266,268 etc. If this gasket leaks air/vac you will not pump the correct amount of fuel or hardly any at all plus you now have an air leak as well. I would be sure of this gasket...also be sure the cyl base gasket is intact and the bolts tight...they have a habit of getting loose on these saws and blowing out the gasket, as it is made of very thin paper. Of course if you are set up to perfom a vac/pressure test you can chase down leaks rather quickly.

 

[Cantdog]

It could be, but it could also be the fuel line. Have you replaced the line recently, if not you should start there.

Yep that too!! Don't over look the filter either, whilst you're there....

 

[MnSam]

Nice to see a thread on this saw. This saw is always in the back of my mind, and on my radar. My dad made some money using this saw years ago, until it blew, I think I remember seeing a connecting rod through the case. I'd like to find one sometime for my own use.

 

[Cantdog]

Nice to see a thread on this saw. This saw is always in the back of my mind, and on my radar. My dad made some money using this saw years ago, until it blew, I think I remember seeing a connecting rod through the case. I'd like to find one sometime for my own use.

Well they are out there and FINALLY someone is producing an aftermarket piston for them. Stock pistons have been NLA for the last 20 yrs or so and until now no one has stepped up to the plate and offered an aftermarket solution. Our very own site sponsor Northwoods Saw now has these gems for sale and are the sole supplier/designer/manufacturer. This means that a tremendous amount of worn out 49sps can be easily given a new life for $29.95 instead of being scrapped. Keep an eye out as in a short time I will be posting up a build thread with lots of pics featuring this piston and the complete restoration of an otherwise dead 49SP from my pile of "Many Jred 49SP parts saws". The follow up will be severe testing over time to see how this piston measures up. I am not affiliated in any way with Northwoods nor is this test sponsored by them. This is simply me building another 49SP with the best parts I can find to give this piston a solid platform to perform from and see where the chips fall...literally!! LOL!!!

 

[keychange]

It could be, but it could also be the fuel line. Have you replaced the line recently, if not you should start there.

The fuel line is clear and the filter is as clean as I can make with high pressure air -I don't think replacements are available.

I used the kit gasket as there was none fitted ... are you sure that this is incorrect, as it does look right and matches the parts diagram.

I mentioned in this forum quite a while back that the fuel was boiling in the tank and I now think that this could also be a sign that the seal is leaking and that hot exhaust gasses are heating the fuel tank.

I checked compression and i get 90 psi - doesn't sound too bad to me for little 2 -stroke, anyone an idea on what it should read?

 

[ncfarmboy]

The fuel line is clear and the filter is as clean as I can make with high pressure air -I don't think replacements are available.

I used the kit gasket as there was none fitted ... are you sure that this is incorrect, as it does look right and matches the parts diagram.

I mentioned in this forum quite a while back that the fuel was boiling in the tank and I now think that this could also be a sign that the seal is leaking and that hot exhaust gasses are heating the fuel tank.

I checked compression and i get 90 psi - doesn't sound too bad to me for little 2 -stroke, anyone an idea on what it should read?

90 psi? I'm suprised it runs. Should be 150-170psi. Cantdog addressed the fuel boiling issue in a previous post. It's normal on these saws.
Shep

 

[Cantdog]

The fuel line is clear and the filter is as clean as I can make with high pressure air -I don't think replacements are available.

I used the kit gasket as there was none fitted ... are you sure that this is incorrect, as it does look right and matches the parts diagram.

I mentioned in this forum quite a while back that the fuel was boiling in the tank and I now think that this could also be a sign that the seal is leaking and that hot exhaust gasses are heating the fuel tank.

I checked compression and i get 90 psi - doesn't sound too bad to me for little 2 -stroke, anyone an idea on what it should read?

Yes I'm sure if you don't have an OEM gasket between the carb and manifold the ones in the kits will not work. Remove the carb and position the gasket on the manifold...on the left side of the manifold at the 9:00 position there is a small hole with a rather "S" shaped corridor that runs to about 11:00 and connects to the small hole in the carb....this entire corridor must be covered by the gasket and air tight. The gaskets that come in the kits work for the tillotson carb fine but not for the Jonsereds saw as they are not large enough to cover in this area.

If you have only 90psi compression you have other problems as well...compression should be at least 140 min. to 170-180 max. in a stock motor. Sounds like you have had some scoring or atleast a partially stuck ring.

These saws boil their fuel, as do the vast majority of all metal saws when run hard in hot weather.. This is why all modern saws have the fuel tank mounted separately and isolated by the AV mounts rather than being simply on the other side of the crankcase partition. That said... I do agree that perhaps after 34-35 yrs it may be time to replace the seals as I said earlier.

 

[keychange]

the small hole in the carb....this entire corridor must be covered by the gasket and air tight.

I don't have the original so I made a paper gasket and it does appear to run better but I still can't get it to idle. As soon as the chain stops the engine dies... is this a possible clutch related issue?

 

[Cantdog]

I don't have the original so I made a paper gasket and it does appear to run better but I still can't get it to idle. As soon as the chain stops the engine dies... is this a possible clutch related issue?

Good..... this is a process of elimination...do the easy stuff first...now reading back through the posts..PB suggested you change out the fuel line. You responded that the line was clear but what PB was getting at was not cloggage but old lines can/will get hard/soft and/or develop tiny pin holes/leaks. The only way to test these is by doing both a pressure and vac test on the dissconnected line itself or simply replace the 9" of line with new. These small 2 stroke engines are very finicky...all things must be correct in order for them to opperate correctly. At idle this most evident and even a tiny pin hole that doesn't leak gas may well leak vac and when the rpm drops so does the fuel delivery of the pump and the more a very small fuel line vac leak becomes an issue to the point of the pump trying to pump but being unable to maintain correct presssure. Generally it is simply a matter of course to replace the line to eliminate the possibliity of it being a problem.. Next you say you installed a carb kit.....there are a couple possibilities here too.

(1) did you replace or clean the tiny final fuel filter in the carb? It is about 1/4" in dia and located under the top cover of the carb and sits down in a hole next to where the fuel enters the carb.

(2) when you had the carb apart did you make sure that there was no cloggage of the idle and main jets? This can be done easily by holding the throttle plate open and spraying WD-40 or similar with low speed needle removed through the needle passage. The WD should come out of the two holes idle holes in the carb bore, one before the throttle plate when closed and one just after the throttle plate when closed. Also make certain that your throttle plate is centered in the bore when completely closed (idle adjustment backed off so it is not touching the throttle arm). Anyway there should be ample WD coming from both idle jets..if not then you will need to pull the welch plug that gives acess to the orifices and clean out what ever crap lies behind. Check the H jet the same way but there is only one hole in the H circuit.

(3) The next issue is the metering lever. This needs to be set so that at rest the lever tang is perfectly even with carb body where it sets. This adjustment is done by carefully bending the lever to the corect adjustment.

(4) Are you positive you have ALL the gaskets/diaphrams/pumps installed in the correct order?? Don't take this wrong but it is worth double checking as it can/does happen.

If all the above things are correct the saw will idle with the "L" screw set at one full turn out. (If it is a carb issue that is.) There is still the possibility of crank seal issues and also perhaps breaker point problems too. But as I said it is a process of elimination and no step is wasted effort on a 34-35 yr old saw.

Also I doubt this is a clutch issue. The clutch should become dissengaged at at or around 2700 RPM and it is very rare that these clutchs fail or get worn as they are robust enough to work on a much larger saw motor than the 49SP.


Oh and one other thing...make certain the cyl base bolts are tight. If you find that these can be tightened any amount do not assume that all is well. Pull the cyl and check the base gasket. It is made of very thin paper and if the bolts become loose this gasket WILL blow and then you have a large air leak. (non or very poor running condition) This has occured twice on my orininal 1977 49SP. If you find a blown gasket you will have to make a new one as these are NLA from dealers or perhaps I can email you a printable template.

 

[keychange]

Wow - ok well that will have to wait to next weekend - great stuff and thanks for giving so much thought to my problem. I will worth through the list - although yes I am sure the gaskets are correctly fitted as luckily I have the exploded view that came with the saw. I will let you know my finding and thanks again.

Andrew:msp_wink:

 

[pioneerguy600]

@Cantdog

 

[cjcocn]

Hi folks.

Can't seem to find any of the brand-specific stickies, so I will post my question here.

Does anyone have the name and contact info for the guy selling NOS J-red parts? His name may be George and I'm sure he was from NY state.

Any help would be appreciated, and if required you can send the info via PM and I will be sure not to make that public in case it results in too many unsolicited PMs for you.

 

[Cantdog]

Hi folks.

Can't seem to find any of the brand-specific stickies, so I will post my question here.

Does anyone have the name and contact info for the guy selling NOS J-red parts? His name may be George and I'm sure he was from NY state.

Any help would be appreciated, and if required you can send the info via PM and I will be sure not to make that public in case it results in too many unsolicited PMs for you.

Well, well, well look who the cat dragged in?? !!! Chris my man...how you been??? Long time.....

Is this the guy?
https://www.ebay.com/itm/NOS-jonser...964100?hash=item5d872f04c4:g:CJgAAOSw-hZcVn0y

Or are you thinking of George Blake?? If so I can't help with that...sorry...

Are you looking for something in particular???

 

[cjcocn]

Well, well, well look who the cat dragged in?? !!! Chris my man...how you been??? Long time.....

Is this the guy?
https://www.ebay.com/itm/NOS-jonser...964100?hash=item5d872f04c4:g:CJgAAOSw-hZcVn0y

Or are you thinking of George Blake?? If so I can't help with that...sorry...

Are you looking for something in particular???

Good morning!

Been pretty good .... keeping busy and keeping out of trouble for the most part.

How have things been for you?

Haven't picked up any new J-reds in a long while, but I did finally see a 535 in person last year. The guy was still using it regularly so wasn't interested in letting it go.

A guy on another forum posted some pics and he had some old J-reds in the background. 110s, 111s, XDs, etc. We got to talking and he is interested in accessing some NOS parts. I figured that I would try to help out a fellow J-red aficionado.

Now that I'm here I think I will have a look around and see what's been happening.

Take care my friend.

 

[Cantdog]

Good morning!

Been pretty good .... keeping busy and keeping out of trouble for the most part.

How have things been for you?

Haven't picked up any new J-reds in a long while, but I did finally see a 535 in person last year. The guy was still using it regularly so wasn't interested in letting it go.

A guy on another forum posted some pics and he had some old J-reds in the background. 110s, 111s, XDs, etc. We got to talking and he is interested in accessing some NOS parts. I figured that I would try to help out a fellow J-red aficionado.

Now that I'm here I think I will have a look around and see what's been happening.

Take care my friend.

Sounds like bulletproof....he's got a pile of nice old Jreds.....

Good to hear from you....hope to see you around a bit more.

 

[cjcocn]

Sounds like bulletproof....he's got a pile of nice old Jreds.....

Good to hear from you....hope to see you around a bit more.

Yep, that's him.

It's getting to be the tail end of winter here -28C (-18F today though) and until the fishing picks up I may grab a few non-running J-reds and go through them. That will give me reason to hang around the chainsaw forum.