UPDATE ON CARB: Bought '07 CRF 150 for grandson...advice please.
I removed and drained the tank; pulled the carb and cleaned it as well as I can on the bench of my workshop. I don't know carbs so I'm certainly not sure that I got into all the places.
Put it back on, poured in about a pint of 93 octane gasoline and tried to start; not even a sputter. So, I unscrew a cap on the top of the carb thru which the throttle is linked; down that throat I spray more carb cleaner or dump some 93 octane gasoline, put cap back on, hit starter and it starts and accelerates for about 2-3 seconds with nothing further. I've done this at least 5 times; each time, starts and accelerates for 2-3 seconds then nothing.
What now? Take the carb to a professional for a rebuild? From my untrained perspective, sounds like fuel is not reaching the carb.