Carb woes, older Craftsman.

rusted · December 28, 2004, 10:07:56 AM

Well, I'm not a pro and I can't afford a new saw that I'm willing to spend money on, so I'm using this older Craftsman my FIL gave to me.

This saw has hardly been used.

I had a problem with it dying when I was bucking. After some work I found I had a chip of wood in the reed valve holding it open and blowing air out of the crankcase. It would still run but not well.

I re-assembled the saw and it wouldn't run at all. In fact, air bubbles would be in the gas line and they don't seem to be moving TOWARD the carb. I can use a dropper and drop fuel down the carb throat and the saw runs on that fuel just fun. As soon as it runs out, the saw quits.

I got a rebuild kit and found both diaphrams 'puckered' when I disassembled the carb. The metering needle looked fine but I replaced the entire assembly anyway. The only check I could find came with the kit, the lever is .06 inches below the gasket surface (if that means anything to you.)

Anyway upon re-assembly the saw still does not run unless I put gas directly in the carb.

I would think that would indicate that I DON'T have an air leak, otherwise why would it run? It just doesn't seem to be pumping fuel.

http://home.comcast.net/~trailrig/carb.jpg
http://home.comcast.net/~trailrig/carbdia.jpg

Admin edit: Photos changed to links due to large width and file size. This helps page loading for our friends with slow connections.

rusted · December 28, 2004, 10:10:58 AM

I have checked all the fuel lines for air leaks, they are tight if I suck on them I get a nice mouthful of gas. :D

The fuel 'weight' works fine, I can open the gas cap and blow in the fuel tank and if the fuel hose is off the carb, fuel runs fine through the whole tank/filter/hose system.

sawguy21 · December 28, 2004, 12:42:23 PM

Replace your fuel filter and line if it is not supple. The metering lever should be flush with the well it sits in. Is the carb to engine gasket in good condition and installed correctly? The small hole has to align with the hole in the crankcase for the fuel pump to work.

Kevin · December 28, 2004, 01:38:29 PM

Check #19 also.
That's the fuel inlet valve.

rusted · December 28, 2004, 01:49:33 PM

I took the carb off to check the hole that needs to align for the fuel pump to work. Guess what, I had the fuel diaphragm/fuel gasket reversed! Doesn't pump fuel that well in that arrangement. :

So I got it running and began to set the idle/low speed/high speed.

I could NOT get it to idle at all. It would idle, then die. Idle, then die. I couldn't even feather the throttle to save it.

Then I tried opening the low speed up further and further. I finally got it to idle, and could keep it from dying if I feathered the throttle. It seemed like it would load up and die.

The manual reccommends opening both adjustments 1 turn. I went with 1 1/4 on the HS and 1 1/2 on the low speed just to be safe. Well, another problem with the saw is the throttle sticks open. And while I was attempting to unstick the throttle, I'm pretty sure I siezed the engine.

So THANK YOU for the help, but with the problems I've had with this saw it's going in the junk pile. With the sticking throttle, I won't even consider selling it to someone else, or giving it away. The trigger would stick inside the handle, and I tried various methods to fix that but never got it to NOT stick open. It was dangerous when cutting and now I'm done with this POJ. I guess that tree will sit in my backyard until I can scratch together enough to buy a real saw.

I hate working on junk.

Al_Smith · December 28, 2004, 02:06:41 PM

What you have there,is a Poulan,dressed in Craftsman clothing.Most likely of the "25" series,by the looks of it.My suggestion,change the fuel lines.Make sure the fuel pump check assembley[some call it a diaphragm],part #16,on your drawling,is installed correctly.Make sure the fuel shut off is set at flush,with the body,this is critical to proper operation.In spite of some negative comments,by some,these little saws,are quite hardy,and dependable.Once you get it running,and you will,make sure the sponge air filter is intact.They have a tendency to get ingested in the engine,when they get old and brittle.A new one,is easy to make from a piece of synthetic sponge.