I have a major bog problem with the bike? It has zero power. The guy I bought it from used race gas and I put in 91 pump gas. It now runs horrible. Could the gas be the problem or could it be something extremly different. I have to really be on the clutch so it will not stall and even then it is ready to die. When I got it I changed the oil, air filter, and sparkplug. The only difference it the gas. The jetting is almost stock, according to the manual, and it has an FMF powerbomb header and T-4 exhaust. I still need to check the valves, but the power loss is so extreme and I have never ridden a bike that is so bad, but could the gas be the problem?