Help with a Homelite String Trimmer

[Axe Man]

Homelite Model UT20002A 25cc 2 cycle string trimmer

Problem: Bogs and stalls when choke lever placed in "Run" position, even after extended warm-up. It will run, with some bogging, in the "Half choke" position. It appears to be running too lean. I checked the following:

Air filter - clean.
Spark plug - OK
Exhaust baffle - clean and no carbon.
Gas is fresh and 50:1 mix as per manual.

See pix...

It appears that the needle valves are either sealed or pressed in. The owner's manual does state that if the unit won't run in the "Run" position to bring it to a dealer for service. Does anyone know if those valves can be adjusted to save a trip to a dealer?

 

[RRich]

My earlier model Homelite had caps covering the needles to prevent adjustment. I pryed them off and was able to remove them to blow out and clean the inside. Reinstalled and readjusted, it ran fine.

 

[Car Luver]

I ahev the same model and was having a running problem also. Messed with it quite a bit.I was using fuel what I thought was mixed correctly.As an experiment I mixed a fresh batch with less 2 cycle in it and then put it in and it started right up and runs fine now.

 

[Shannow]

Only problems I've had with my homelite (and FIL with his Ryobi - identical) are old fuel.

New fuel (I use 30-1 or richer) and it's a dream.

 

[Brett Miller]

I'll tell ya what I did with mine....I bent the shaft into a U and put it in the garbage. Drove to the Echo dealer and purchased a SRM210. Life is too short to put up with ---- equipment.

 

[yeehaw1960]

Yep. She's starving for gas.
Grab the plastic air screw cover with pliars. Pull it off and throw it away...just don't tell the EPA. Don't stick a screwdriver on it and pry, because whatever the screwdriver is leaning on might break. Turn the screw in or out 1/4 turn at a time until it's running correctly. If it has two screws, one will be marked L and one H on the carb right beside the screw holes. The low one is for idling and should be adjusted while it's doing just that. The high one can be adjusted by suddenly giving it gas to accelerate. If it bogs, adjust the High screw 1/4 turn at a time until it instantly revs when you peg the gas. If that doesn't fix you up...
If you look at the carb, you can tell it's very easy to remove and clean. Take a digital photo of it at different stages of disassembly and save yourself lots of frustration. You can clean the carb up with Gumout and compressed air. Careful...under one of the covers there is a small screen sitting in a recess that will disappear forever with one blast of air..lay your finger partially over it to keep it in place while blowing. Before removing the air screw, carefully turn it in until it bottoms out (not too hard!) counting the the number of turns it takes to screw it all the way in (for your reference when reassembling). The diaphragm fits on with the circular piece towards the inside when reassembling. I always used to forget that. When putting the screw back in, turn it all the way in, and turn it out (counting the same number of turns). After it's all back together and running, adjust the airscrew as described above. Sounds complicated, but it's really very easy (if you take digital pictures). Addtional tips: Don't remove the screw under the diaphram. It takes steady experienced hands to get that back together right. Just spray the area liberally with gumout. Also, when you stick the spray tube inside a hole on the carb and push the gumout button, it might come out another hole and spray you in the face. Careful!
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[yeehaw1960]

Oh, and if the airscrews are blank (without slots) as much of the newer stuff has, a little work with a dremmel tool with a cutoff wheel and you have instant slots! Now, I'm not talking about the obvious "plug" that some of them have next to the single adjustment screw.

 

[jsharp]

Ugh, EPA engines.

My Ryobi is so lean if you try to run fuel mixed with more oil than 50-1, it needs 1/2 choke until it's super warm. Now *that* really helps lower pollution doesn't it...

 

[yeehaw1960]

Yup. My Weedeater brand blower and some of the whackers I've worked on have air "screws" that have no slots, but have splines on them that you need a special tool to adjust. Same thing...I cut through the clever guard they put around them and cut slots in the heads.
It was EPA rules and generally cheapness that turned Tecumseh mower engines into such a fiasco of hidden passages and plastic.

 

[Axe Man]

It's fixed! I tried to pull out the plugs as mentioned. They came out about 1/8 inch and then stopped. It appeared if I pulled with any additional force they would break. So I decided to cut the tabs off both plugs and try to turn them. Success! They would turn. So I turned the red plug approx 1/4 turn counter-clockwise and fired up the trimmer. It ran perfectly! No more bogs, idles without stalling, and best of all operates in the "Run" position with lots of power.

Thanks to all for your suggestions.

 

[Jim 5]

I had the same problem with the same exact trimmer. I ended up taking the carburetor apart, cleaning everything and reassembling. I'm not sure what I did, but it ran perfectly after that. It was around 8 years old at the time.

 

[Al]

Quote:

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I'll tell ya what I did with mine....I bent the shaft into a U and put it in the garbage. Drove to the Echo dealer and purchased a SRM210. Life is too short to put up with ---- equipment.

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Exactly..that's what I did. I pried off the fuel adjust needle valve to richen it. That worked for a while. There were other issues. They are basically junk (IMHO)

 

[Al]

Quote:

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Drove to the Echo dealer and purchased a SRM210.

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Thats the model I have. The problem with this unit is that you have to operate it left handed. If you operate it like a conventional trimmer it kicks up all the ---- at you bc the rotation is opposite that of a curved handle type (with no gears).

 

[Brett Miller]

I do have to say it was satisfying when I put the Homelite out to pasture...

 

[spec]

More often than anything is the muffler port stops up. Take the muffler off and look at the rod and piston. There will be carbon build up, this makes the engine bog down.