Craftsman Weedwacker won't stay running

Hey folks! I'm running out of ideas here and could use some help. I've got a basic Craftsman 2-stroke weedwacker (model 316.711370) that I can't keep running. I used it a few times after I bought it, then it sat for a winter with fuel still in it (okay oops). It never ran great, but since that winter I haven't been able to get it to stay running at all. With the choke on, it will run until you start to use it, but if you set the choke to 2 or 3, no matter how long it warms up, it will die within 30 seconds if you let it idle, or 2 seconds if you try the throttle. I tried fresh fuel/oil mix, cleaning the carb, replacing the carb, and replacing the spark plug. I tried adjusting the idle screw but it doesn't seem to matter. I called a repair shop but they told me it would cost more to fix than it would to replace. However, I'm considering paying for it anyway just so I know what the cause was. Anyone have any good ideas what else to try before I do that?

 

If it sat for extended time then the carb is all gummed up from varnish and needs to be completely disassembled, cleaned, and reassembled.

Is that what you did?

 

He said he replaced the carb. Why that much time and money for a POS basic cheap weedeater, I dunno.

Spikey, that's a good shop that gave you good advice. Buy another, run it on a little bit heavy oil mix, run it dry at the end of the season, and fog the cylinder. It will probably last 4-5 yrs if yer lucky. That works out to pretty cheap.

 

You're considering paying more to fix it than to replace it? Is it sentimental?
Are you running ethanol fuel in it? If so, any trimmer you have is probably going to have this problem eventually. When you replaced the carb, was it with a brand new one?

 

Ha ha ha - hey folks. No it's not sentimental, and yes you are all correct that fixing it is by no means worth it. Nor was it worth it when I first disassembled and cleaned the carb, and when that failed, completely replaced it. More than anything, it just bugs me. A two-stroke engine seems so simple, I should be able to fix it, and I want to know... you know, for that whole "learning" thing...

I used pump gas (mixed with oil) the first year that probably had 10% ethanol, but since then I'm using the pre-canned stuff so no ethanol, and it hasn't made a difference.

If no one else has any ideas, that's fine, even that would make me feel better. But if there are any other ideas what could be wrong with it, I'd love to hear them.

 

Replaced it with a new carb? Or another from another trimmer? I'd say you have carb problems most likely. If the fuel filter broke off the fuel line, it would stop up a new carb pretty quickly.

 

Make sure the cylinder barrel gasket and any crankcase seals are air tight as air leaks affects both the pressure and vacuum conditions of the engine.

 

Thanks all! Yes, after rebuilding the original carb didn't work I bought a totally new one from Sears. I will check the gasket and seals. I could see how an air leak would make sense.

Thanks for all the help!

 

If you can get it started spray/dribble carb/brake parts cleaner behind the carb and along all mating surfaces if the engine tempo changes you have an air leak and can take the appropriate action, also check thee fuel lines if they haven't been changed they most likely have a crack in them. Have a good one. Geo