Troy-Bilt TB20CS No-Start -- Engine Surges then Dies

[lothian]

My Troy-Bilt TB20CS worked fine in the Fall before I packed it away dry. Smash-cut to Summer 2021. After topping off the tank with nummies and priming, I find the trimmer behaves consistently as follows: First pull, full choke: a brief catch. Second pull, half-choke: the engine surges then dies.

 

I figure this is a symptom of fuel starvation, so I presume either/both a dirty carb and/or fuel line issue. I remove and disassemble the carb, blow carb-cleaner thru its orifices, and install a new diaphragm; I also replace the lines. After reassembly I get no change. I suppose I could mess with the "low" needle, but this seems unlikely.

I exhausted my t'shooting skills and I'm officially stumped. Recommendations? Suggestions?

[gerardj]

rebuild the carb,...again.

drop it in a solvent can or ultrasound it, run wire through ports and jets or you'll be doing it again.

[lothian]

After a third rebuild and after a stealthy overnight lavage in the wife's ultrasound, it still wouldn't work properly. So I swapped the thing with an aftermarket carb. The TB20CS started up and runs, but the new carb leaks fuel... of course.

 

<plaintive sigh>

[wingless]

I feel your pain...

 

Been through all those steps, except the ultrasonic cleaner is mine and is used to all sorts of chemicals.

 

My 40 year old Snapper Hi Vac finally gave up the ghost, so I just purchased my first lawnmower and am loving my Toro Model 21386 self propelled 21" walk behind.