Craftsman 2 stroke 25cc string trimmer only runs on 80% choke

[primerbulb120]

That's not possible. You either have the wrong screws or are looking at them incorrectly. Could you post a picture of what you're referring to?

 

[tbzep]

Every time I've had to run a trimmer or saw with the choke open the cause was air leaking into a cracked fuel line or primer bulb.

 

[TylerFrankel]

That's not possible. You either have the wrong screws or are looking at them incorrectly. Could you post a picture of what you're referring to?

You were right. I don't know what I was thinking, but there was one closer to the engine than the other. I got the dremel on the screws and adjusted them, until the engine stayed idling and ran smooth at max RPM without bogging down on no choke. Had to slightly increase idle screw. The engine takes time to warm up, like a normal 2 stroke, but after it warms up it stops bogging and runs fine.

 

[bertsmobile1]

VEry Very Very important on these engines is to adjust them properly.
The H screw is done first, wound in till the engine faulters then out till the engine faulters then set 1/2 way between these two .
Most people adjust it till the engine runs fastest which is too lean and the engine will overheat & sieze.
I do this without the air filter on so with the filter the settings will be just a touch on the rich side which keeps the engine cooler.

After the H is done then the L gets done, the same way.
Finally the idle screw gets screwed out till the head stops turning.

Depending upon just how far the engine was out of adjustment the whole process might need to be done a couple of times.

The other rookie mistake is to tune the engine with no load.
You must have the line out full length or the trimmer will run great in the workshop but have no balls in the grass.

Some times I have needed to move the guard out of the way and run the line out longer to put enough load on the engine.

 

[primerbulb120]

Another thing to watch for, if you richen the L circuit it will affect the H circuit too. So after adjusting both, check the H side again to make sure it's still correct.

 

[TylerFrankel]

VEry Very Very important on these engines is to adjust them properly.
The H screw is done first, wound in till the engine faulters then out till the engine faulters then set 1/2 way between these two .
Most people adjust it till the engine runs fastest which is too lean and the engine will overheat & sieze.
I do this without the air filter on so with the filter the settings will be just a touch on the rich side which keeps the engine cooler.

After the H is done then the L gets done, the same way.
Finally the idle screw gets screwed out till the head stops turning.

Depending upon just how far the engine was out of adjustment the whole process might need to be done a couple of times.

The other rookie mistake is to tune the engine with no load.
You must have the line out full length or the trimmer will run great in the workshop but have no balls in the grass.

Some times I have needed to move the guard out of the way and run the line out longer to put enough load on the engine.

Well I guess I'll go get it back from him, I had no idea about these things. Plus, he had like no string in the trimmer so I bet its wrong. I'll get back to you all soon. Thanks!