Poulan Micro 25 problem

[Labman]

I have an old saw that sometimes runs fine, and sometimes just will not draw gas into the carburetor. Been that way for a long time. It is an old Poulan Micro 25 with a Wabro WA19A carburetor. What ever the problem is, it comes and goes. A couple of months ago, it ran fine all day on a big project. Then it quit, and hasn't run since.

We had a storm last week, and I have a mess I need to clean up now.

I rebuilt the carburetor and replaced the fuel line. I can draw gas out the fuel line with a syringe. If I slosh a little gas in the carburetor, it will run a few seconds. It just will not pull gas from the tank.

I am looking at the needle valve. It is actuated by a lever with a spring to close it, and has a diaphragm that pushes the lever to open it. The lever has very little range of movement. As installed, the spring is almost completely compressed, and the lever bottoms out on the carb body. Should I bend it up? Since the kit had a new one, I do have a spare.

Even a link to a picture of the assembly might be a big help.

I am new here. The word at http://theoildrop.server101.com/ is to bring serious questions about chain saws here.

 

[Kenskip1]

Labman

I have had virtually no experience with Poulans however, from the sound of your query it would seem to me as if you are not getting any vacum from the bottom end. On a husky,the impulse is built into the side of the cylinder. Their is a small grommet that may have a crack in it causing an air leak thus preventing the saw from running. I was thinking about a possible gas line with an air leak but you seem to have narrowed it down.I hope this may help, Ken

 

[motti]

I love the old Poulans, but I'm no good at the carbs. Wish I could help.

 

[romeo]

It could also be the check valve in the gas tank. Loosen the cap and run it and see if it changes.

 

[scottr]

Metering lever adjustment

Labman , for instructions on adjusting the metering lever on the walbro WA carb you can find it on acresinternet.com then click on chainsaw collectors corner , then click on carburetors , then click on Walbro , then click on WA .

 

[retoocs555]

It also sounds to me like you aren't getting vaccum.

There is a hole in the base of the carb that should line up with a hole on the case, and the intake gasket that goes between should also have a hole that lines up in the same place. Make sure all your holes are inline, often the gasket will block it. Check to make sure it's not pluged or gummed up.

It could also be because of the lever you speak of. If the above doesn't work try bending the lever so that it is flush with the top of the carb body.

 

[Labman]

Thanks for the answers. It seems to be responding to adjusting the lever. Bending it out to the plate gave me a way to much gas. While checking an intermediate setting, I discovered it was sucking air. I think I have too much extra fuel line in the tank. It looks like with a little fooling around, I am finally going to get it going. I decided to quit for the night. What I don't understand is if the lever was set way too low, why did it run part of the time?

For an intermittent problem, the gas cap sounded likely, but doesn't seem to be the case.