Older Craftsman 42cc Carb Starting Point?

[ChillyB]

Just a simple free backup saw that doesn’t run well. Didn’t run at all until I unstuck the carb gasket check flaps and set the coil. Now I can get it to fire but runs rough and won’t stay running.

Carb looked pretty clean, which I didn’t expect. Puffed a little sea foam into the carb while running. I think I need a reasonable low and high mixture starting point so it’ll at least idle, allowing me to dial it in. Couldn’t find reference to initial settings yet. Any guesses on starting point for a little 42cc carb?

Thanks
ChillyB

 

[ChillyB]

And everyone likes pics, even a poor boy Craftsman, right?

 

[hwrdpromac7900]

Both needles 1 to 1 1/4 turns counter clockwise for base setting.

 

[Wood Doctor]

Amazing how many guys hang onto these saws. I picked this one up 12 years ago and got it running after tightening a loose spark plug:
It runs today and makes a good saw for loaning to a neighbor. Post #3 needle adjustments are good. I lean toward 1.5 turns and adjust from there based on my ear. Raise the idle up a hair to make sure it doesn't die on you while you adjust. Lower that later to stop the chain from running on its own at idle speed. Good Luck!

 

[3000 FPS]

Just a simple free backup saw that doesn’t run well. Didn’t run at all until I unstuck the carb gasket check flaps.

Thanks
ChillyB

I think I would order a carb kit. I think those are reed valves.
Worth fixing.

 

[ChillyB]

I sprung for an entire carb (walbro) but the choke lever isnt a match. The good news is it seems to be a match for another 18" 42cc craftsman in need of a carb (I turned into a junk-saw-whore, I hope it's a phase). I'll get a kit this time since after disassembly the carb looks very clean.

I pick up these old cheap/free saws because a person should have backups, and able to help a neighbor with a loaner that won't break their heart when they burn it up. Primary saw is a clean 1998 Husqvarna 350 that also deserves some attention to keep it going. Not a logger, just a homeowner who likes to tinker.

 

[3000 FPS]

It does not matter if the carb is clean. There are diaphragms in there that can become stiff and not function well and the saw will never run right as long you have those in there.

 

[ChillyB]

Point me at $25 Craftsman saws needing a $10 carb kit and I'll grab them up all day long. Trying to get my kids to learn how to make "broken" stuff work. Saws are easy, cheap, fun. Next step might be an old Gravely L-model walk-behind tractor. Graduation is fixing up an old Jeep. This one is in process:

 

[3000 FPS]

I sprung for an entire carb (walbro) but the choke lever isnt a match. The good news is it seems to be a match for another 18" 42cc craftsman in need of a carb (I turned into a junk-saw-whore, I hope it's a phase). I'll get a kit this time since after disassembly the carb looks very clean.

I pick up these old cheap/free saws because a person should have backups, and able to help a neighbor with a loaner that won't break their heart when they burn it up. Primary saw is a clean 1998 Husqvarna 350 that also deserves some attention to keep it going. Not a logger, just a homeowner who likes to tinker.

I just tinker with this stuff too. I do cut firewood though.

 

[3000 FPS]

Point me at $25 Craftsman saws needing a $10 carb kit and I'll grab them up all day long. Trying to get my kids to learn how to make "broken" stuff work. Saws are easy, cheap, fun. Next step might be an old Gravely L-model walk-behind tractor. Graduation is fixing up an old Jeep. This one is in process:

Nice ChillyB. Once you have knowledge they can never take that away.

 

[ChillyB]

I have more weekends of firewood work behind me than in front of me so trying to resist urge for a bigger new saw. The Husky 350 served me well when I cut a fair amount. It's certainly adequate for my needs going forward if I update the carb boot and maybe a carb rebuild.

For the price of a new bigger saw I can buy a lot of coal. Am I the last man heating with coal? Last house had wood stove, this one had a coal insert. Gotta say, I do like the coal better than wood. That said, I have stack of fire brick to convert to wood use if/when coal isnt available. And a few trees that need to come down. Can't have too many ways to stay warm.

 

[ChillyB]

I'll order a carb rebuild for this particular saw before wearing out my arm. Then onto the other older Craftsman, which is cleaner and seems used little. Got it for $20 from local Stihl dealer where it was abandoned.

Then onto the Stihl 009L, which I want very much to be a success. I'm in deep at $40 for this one.

 

[Tomos770]

Dont forget to change seals behind carburetor and between cylinder an carburetor flange!

Have Partner 351 (Poulan 2150, Craftsman....) saw....for the "entertaining" purposes To learn how to port....modify saws....

Have changed everything on it....from crankseals to new fuel lines and both filters (air&fuel)....even purge valve.....and it doesnt want to work ok.... I have to press that purge valve if I want saw to run

The only thing that I didnt change are those seals between carburetor and cylinder....

It is obvious that saw is unable to pump gas by itself....so have to replace those seals also (they are old,cracked and stiff....original from 1997)

 

[ChillyB]

Got it idling but bogs under throttle (no load) even with high speed screw way out. I think its way lean. Ordered carb kit and gasket kit. Might not be the problem but start with what is simple, cheap, and probable. So $50 into a free saw that'll be worth $50 when running right.

 

[Tomos770]

Check also its spark arrestor inside the muffler! And open it up a little (search my posts in saw porting 101)

 

[3000 FPS]

Got it idling but bogs under throttle (no load) even with high speed screw way out. I think its way lean. Ordered carb kit and gasket kit. Might not be the problem but start with what is simple, cheap, and probable. So $50 into a free saw that'll be worth $50 when running right.

You cannot put a price on education and education will serve you a lifetime.

 

[Tomos770]

Thats the reason why I still have my Partner 351...its for educational and learning purposes mainly

 

[3000 FPS]

Yep I barter for things using my chainsaw knowledge.

 

[hwrdpromac7900]

Got it idling but bogs under throttle (no load) even with high speed screw way out. I think its way lean. Ordered carb kit and gasket kit. Might not be the problem but start with what is simple, cheap, and probable. So $50 into a free saw that'll be worth $50 when running right.

If it bogs when you snap the throttle then richen up the low side. To much fuel on the high side could cause the bogging.

 

[leecopland]

Dont forget to change seals behind carburetor and between cylinder an carburetor flange!

Have Partner 351 (Poulan 2150, Craftsman....) saw....for the "entertaining" purposes To learn how to port....modify saws....

Have changed everything on it....from crankseals to new fuel lines and both filters (air&fuel)....even purge valve.....and it doesnt want to work ok.... I have to press that purge valve if I want saw to run

The only thing that I didnt change are those seals between carburetor and cylinder....

It is obvious that saw is unable to pump gas by itself....so have to replace those seals also (they are old,cracked and stiff....original from 1997)

Maybe the fuel lines to purge valve are reversed, very common in these cheap pick ups.