Check your intake boot for cracks. It sounds like your sucking to much air. Dumping gas in the cylinder means its not sucking gas from the carb. It could be small crack thats just getting worse over time. I would start there.
"If you are going to piss like puppy, Don't Get Off The Porch"
Trikes:
84' Suzuki ALT185 (old Orange)
85' Yamaha 225DX, piped and spaced ( First Girlfriend)
Quads
87' Yamaha Banshee, built and very very fast (The Whore)
01 Yamaha Raptor 660, built and piped (The Beast)
03 Suzuki Vinson, 26's and piped (The Crowd Pleaser)
Once apon a time:
85' Tecate 300 alky flattacker, 6 in over swingarm, 88 Suzuki 500"Quadzilla"PIA , 91 Yamaha Warrior Built and Modded. (luved that Baby Tank)