Small Engine Problem... Yet Again !!

Since you guys were so helpful in the past I come to you yet again for advice. Please, bear with me.

This time the problem is with a 25cc 2 cycle weed trimmer. Problem I am having is simple. It won't pull any gas from the tank. I tried pressing the primer bulb several times and I hear the sound of air compressing and being pulled but there is no suction on the fuel line to the tank. Yes, I checked to make sure the fuel line has no leaks or homes and yes, I removed the primer bulb and checked it for any cracks or leaks. It looks fine... no leaks no cracks. The gasket that seats between the primer mechanism and the body of the carburetor seems goos. No tears or rips or anything. I am thinking that perhaps there is a clog somewhere, since it was working fine when it was last used last season. Perhaps some gas turned to varnish over the winter and clogged up the small orifice in the primer mechanism. I am soaking it in carburator solvent overnight to see if it dissolves any possible clogs.

Of course as usual I ask if anyone has any spoecific ideas and/or specific things I should look at before I start ripping into or rebuilding the carburetor. As usual any and all help/suggestions, etc. are deeply appreciated... Meanwhile the weeds in front are getting so tall they are sprouting seeds :)

IIRC there is a little diaphragm check valve in the carburetor on those. If it's bad, you'll see what you're seeing.

Pull the fuel line from the bulb off at the carberator. Give it a few pumps and see what happens. If the fuell comes out the carb is plugged, if not, the line is plugged. Those bulbs are only good for a couple of seasons, less if you don't drain the tank and run the fuel out of the carb. The fuel line and bulb is only a few bucks on Ebay, just be sure to get the one for you model because the fuel lines are various sizes, and usually go through a hole in the plastic fuel tank. Too big=no fit, too small=leak. To make it easier, cut the new fuel line at a sharp angle on the end before trying to push it into the tank. Good luck

Thanks. I found out where the problem was. It was inside the tank. In the tank where the fuel pickup tube enters there is a small plastic nipple. Attached to that nipple is a short piece of silicone fuel tubing running to a clapper/gas filter. Well, what happened was the piece of tubing fell off that plastic nipple and was just rolling around in the tank. No wonder it wasn't pulling in gas. I found that the end of the tube where it attaches was ripped, most likely due to deterioration of the fuel tubing. I clipped the ripped end off, reattached it and managed to get it to run long enough to trim doown the weeds out front. But it still needs work. I am going to have to get new fuel lines, a new clapper/filter and I am also going toi get a carb rebuild kit. I am going to check out Home Depot or a local lawn and garden centre. Otherwise the engine is good and I think the ol' trimmer has a few years of life left in her.

P.S. The fuel lines look like the same sizes we frequently use in gas powered model airplane and helicopters (cars and boats too) . If I can't find them at Home Depot any good RC Hobby shop should have them.

I'm having this same problem with a Kubota portable generator. Runs great off starter fluid shot in the carb, but won't run off the gas tank. Will have to try this next weekend.

Wish I could help but 2 stroke motors are not my specialty. My problem with them has always been getting the mix exactly right.

Among the approximately 10,000 jobs I've held in my life was Homelite factory-trained chainsaw repair tech. The #1 problem I encountered there was carburetors clogged up with oil and varnish from old gasoline. #2 was fuel lines that had been eaten away by sitting in gasoline for long periods of time.

My advice: before you put a 2-stroke engine away for storage for any amount of time, always drain the tank and run the engine until it runs out of fuel. Do that one simple thing and you'll prevent about 90% of the problems typically encountered with 2-stroke egines.

ethanol is a problem as well. you know the crap they water down gas with.

I got a old craftsman rider mower out back motor is shot cause of fucking cheep ass ethanol watered down crappy gas

Quote:

---

Originally Posted by W2IBC

ethanol is a problem as well. you know the crap they water down gas with.

I got a old craftsman rider mower out back motor is shot cause of fucking cheep ass ethanol watered down crappy gas

---

Hell on carb floats. I know when I was looking at BMW airheads, there were conversion kits from Bing to replace the floats with ones that wouldn't break down on "E10".