Echo PPT-266 bogs down when lightly given throttle, but not full throttle

[broken_wacker]

I start it and it idles fine, doesn't die after several minutes. I then apply a small amount of throttle and it bogs down. If I pull the throttle all the way it runs as you would expect.

I'm no expert on 2 cycle engines, but am very interested in learning so I can keep my 2 cycle equipment running great.

The only thing I can think to do is adjust the carb low screw. Is this what you would recommend based on the information provided? Are there any other suggestions I should look at?

Thank you.

Replaced
--------
* Air filter
* Fuel filter
* Spark Plug Plug
* carb rebuilt (the kit didn't contain the needle, but the diaphragms and seals)
* cleaned the carb with carb cleaner
* fresh gas; the same batch of gas is in my echo chainsaw, blower and hedge trimmer and working great

Checked but did not replace or repair
------------------------------------------
* Spark Arrestor - looked rust colored, but could see through all parts of screen
* Took fuel line out and made sure I could see through the entire fuel line so put it back on

 

[bertsmobile1]

:welcome:
Most likely
Your low speed jet is out of adjustment.
Start the trimmer let it run 10 minutes to warm up.
Then slowly turn the L needle.
It is a fuel needle so in = lean & out = rich

Turn it in till the engine starts to faulter and note the position of the screwdriver
Turn it out till the engine starts to faulter and note the position of the screwdriver.
Then return it to a position as close to the middle of these 2 positions as you can.

If you can turn the needle more than 1 full turn in either direction without the engine stalling out then the idle passageways are blocked or the needle is damaged.

Butterfly throttled cube carbs are two carbs in the one body.
One does low speeds and the other does high speeds.
Somewhere around 1/4 throttle it swaps from the Low to the High.
Because the needles are spring loaded, they tend to open up over time making the engine run rich.

If you get some one to hold a sheet of white paper against the exhaust opening you might just see the exhaust going black before the engine stalls out.

The walbro web site has really good manuals on it but you have to snoop around to find them.
The link is right at the bottom right of the page.
I would post the URL for you but my ISP has choked my connection speed to 256k so it dates a week to open graphics rich web pages.
Regardless of who makes them, all cube carbs work the same way.