My GSR has a hard time starting lately when it's cold, but it starts fine 95% of the time when it's warm. It just cranks and cranks like there's no gas in the tank, but it always evetually starts, but it's getting worse the last couple weeks, taking more cranking to start like something is slowly crapping out on me. My bud's first guess was the fuel pump, I still have the origional one in there. It's 156K/11 years old, been running a 12:1 engine build for the last 17K/1.5 years. What's the most likely problem?