Recently, I hit a hill that required about 10 seconds of full-on second gear with a click to 1st in the last 40 feet of rough, rutted steep lip. The BRP died going right over the top. I have stock gearing and am unplugged. Over 3 successful attempts, the only thing carrying me over the top was lady luck and Isaac Newton. That was consistent. I had about a 1/4th tank - but on attempts 2 & 3, I leaned the bike over to get the gas on the petcock side before each attempt. Nothin' different. She was dying as I went over the top. So would you start? I have the manual, the aftermarket Air filter is routinely cleaned. My first instinct is to pull the carb and clean the jets. I've had the CDI (Black Box) on the Honda's go haywaire about every 4-6 years, but I think this is too specific for that to be the cause.