Jonsered 49SP Project

[R/C Pilot]

OK, I have to ask. What kind of RC pilot are you? What do you fly? I grew up flying with my dad and brother, but haven't flown in years. Dad was always into the bigger planes with gas engines. Started with Zenhoas (G38), but then we got into aerotowing and had some monsters. The coolest one was a 46% Ultimate. I think that had a DA 150 or 200 twin. Don't get me wrong we still flew the smaller stuff. I learned when I was about 10 on a .20 powered all foam cub, nothing a little epoxy could fix to get that thing up and running after all the beginner hard landings.

P M sent about above.

Looks like you are doing a good job and not getting ahead of yourself, and Cantdog is walking you through a first class carb rebuild.

This is the kind of thread I like to see on this site.

Keep up the good work.

 

[telemaster]

Day 3

New final fuel filter installed
Metering lever set flush to carb body
Cylinder bolts torqued
Muffler removed, cleaned, and reinstalled
New spark plug installed

Almost there.....

I got a call from the Husky shop today... my new carb manifold gasket is here. They caught me unprepared as I haven't yet measured what size fuel line I need to buy. I want to save a trip and get the gasket and fuel line at the same time--today after work! Does anyone know what size fuel line I need for this saw?

Thanks in advance.

 

[telemaster]

Day 4

Got the fuel line. For the next guy it has a 1/4" OD.

Manifold gaskets are below for reference: Husky 262 gasket, carb kit gasket, and original gasket.
View attachment 283409

Here is a picture of the carb installed. You can see the throttle linkage does not sit flush against the bushing on the carb. Just doesn't seem right, but maybe it is. Anyone know for sure?

View attachment 283410

Thanks. Looking forward to hearing her run.

 

[R/C Pilot]

Got the fuel line. For the next guy it has a 1/4" OD.

Manifold gaskets are below for reference: Husky 262 gasket, carb kit gasket, and original gasket.
View attachment 283409

Here is a picture of the carb installed. You can see the throttle linkage does not sit flush against the bushing on the carb. Just doesn't seem right, but maybe it is. Anyone know for sure?

View attachment 283410

Thanks. Looking forward to hearing her run.

I looked at mine and it has about a 1/4" gap between the throttle linkage and roller. When the nylon guide is in place the linkage does not stick out of the guide until you pull the throttle.

 

[Dan_IN_MN]

Looking good! Nice job on your Jonsereds 49sp. Your s is missing in your sig. I like the older Jonsereds and am a bit particular on getting the s on the older ones.

 

[telemaster]

She's all done

Thanks for all the help guys. With your help and a lot of patience she is running real nice now. I even cut a little firewood with her this weekend. A nice little saw for sure.

It wasn't as easy as just bolting her together and pulling the rope. It did fire up with the throttle lock on and full choke after 3-4 pulls, then choke off and one more pull and it came to life. It wouldn't stay running though. I admit to getting frustrated and the thought of taking it to the local shop for a tune entered my head. Then I just started tinkering with it. I reset the H/L screws to one full turn out each, and got the idle adjuster correct so it will sit there and purr without the chain moving. Then I held it wide open and tuned the H screw until it leaned right out, then back until it started 4-stroking. Runs like a top now.

View attachment 283852View attachment 283853

Oh, and I fixed my signature too. Thanks for the catch! :msp_thumbup:

 

[Cantdog]

Excellent!!!!! These are not the fastest 50cc saws but cut well and are very dependable....

 

[R/C Pilot]

GOOD JOB Glad to hear that all worked out.

 

[James49sp]

Jonsered 49sp no longer starts :/

Hi im new to this forum and this is my 1st post.

Here is the story...i have a Jonsered 49sp for a few days,it was starting and running,the night before it wouldnt start again i tinkered with the carb adjutments and it was reving up and idling perfectly. The next day ( dont ask why,i have never done this to a saw before) i decided to power wash it. after doing so i tried to start it a few times but it would not go,i checked and there was a good spark at the plug (and still is) i then removed the carb (Tilletson dated 1963),disassembled it and cleaned it out in clean fresh petrol ( carb was spotless,no dirt in internal filter etc) reasemmbled it and put the saw all back together,tried starting but still no luck,if i put a bit of petrol down the plug hole the saw will run with choke on and full throttle for a second or two then cut out again,fuel filter is clean in tank (i also cleaned out the tank,fresh fuel etc) carb has been reset to 1 turn out on each screw.....one pipe comes from the tank to feed the carb and the other from tank sites beside the cylinder not attached to anything,is this correct,probably a breather? Any advise greatfully received.....

 

[Icedogs28]

Nice work telemaster, and what a great looking saw! cant believe you stole one that clean for $30! Enjoy!

 

[Cantdog]

Hi im new to this forum and this is my 1st post.

Here is the story...i have a Jonsered 49sp for a few days,it was starting and running,the night before it wouldnt start again i tinkered with the carb adjutments and it was reving up and idling perfectly. The next day ( dont ask why,i have never done this to a saw before) i decided to power wash it. after doing so i tried to start it a few times but it would not go,i checked and there was a good spark at the plug (and still is) i then removed the carb (Tilletson dated 1963),disassembled it and cleaned it out in clean fresh petrol ( carb was spotless,no dirt in internal filter etc) reasemmbled it and put the saw all back together,tried starting but still no luck,if i put a bit of petrol down the plug hole the saw will run with choke on and full throttle for a second or two then cut out again,fuel filter is clean in tank (i also cleaned out the tank,fresh fuel etc) carb has been reset to 1 turn out on each screw.....one pipe comes from the tank to feed the carb and the other from tank sites beside the cylinder not attached to anything,is this correct,probably a breather? Any advise greatfully received.....

Hmmmm.....many varibles...have you inspected the fuel line from the filter to the carb??? A problem with starting after a water treatment is generally electrical in nature.....but you say you have good spark....Hmmmm.....When going through a carb you should really put in a new carb kit as well as clean it if nothing more than to eliminate the carb as a problem...I believe water is the problem...somewhere......more info will help....