Trimer won't keep running.

[Jack Rabbit]

My trimmer, "weed eater", won't keep running and is really hard to start. Troybilt TB25CS 2-cycle.

Symptoms:
- Really hard to start. Used to be easy.
- Runs ok for a minute or two then stops.
- Usually stops instead of idle.
- Oily stuff on muffler.
- Some white/gray smoke that I didn't notice before.

Actions taken so far:
- Replaced the spark plug. Set gap per manual.
- Cleaned air filter.
- Cleaned spark arrestor screen. Some of it won't come off. It is mostly clean though.
- It still had trouble so tried it without the spark arrestor screen to test if the partial blockage was a problem. No change.

I suspect improperly mixed fuel, too oily, because of the smoke and the oil on the muffler. I'll mix fresh tomorrow and try it.

I mixed right. The mix is about a week old. Not many customers so a gallon lasts. It is hot here and the plastic fuel can swells up. Sometimes I open the small cap, the air thing, on the can to release the pressure. Now I think that the evaporated stuff making the can swell is gasoline, the alcohol they put in it here, or both ... leaving the oil behind and changing the mix ratio.

Note: I found that Hoppes No. 9 powder solvent and a wire brush are good for cleaning the spark arrestor screen.

Any ideas or suggestions?

[mark123]

... I found that Hoppes No. 9 powder solvent and a wire brush are good for cleaning the spark arrestor screen. ...
A gun enthusiast, eh? :)

It could be many things.

Is the magneto firing? Does the plug spark when you try to start it? Once you get it running have you tried adjusting the carb? I had one where the choke wouldn't stay in place and would fall to the closed position while it was running causing it to flood. I had to tie it in the open position.

[NewLeafca]

If you have an adjustable carburetor and turning the "H" needle out 1/4-1/2 turn has no effect you will need to remove the carb and soak and service it. If the riching of the needle does have favorable results and the needle doesn't have limiter caps, you will want to see exactly how many turns out the needle is now at in order to run well. If it is out more than two turns in order to run well this indicates you have a restriction in the carburetor and should opt to service the carburetor anyhow.

You may want to remove the muffler and have a look at the cylinder before you perform any service that involves money. A worn piston and/or cylinder will not create enough vacuum to draw in any fuel mixture and give the impression of a lean condition.