1994 900RR lacking power?

Ok I have an old school 900RR and it just doesn't seem to have the power it is iconic for. I have never been able to power up a wheelie on it and it will only do one if I clutch it up in 1st gear. Plus my buddy has a 2005 GSXR 750 and I barely keep up with him. Here is a little knowledge about the bike: it has 34,000 miles, a stage 1 jet kit, vance and hines power pak, d&d full exhaust system, and the fuel pump went out so it is gravity fed at the moment but it doesn't run any worse without the fuel pump. Does anyone have any idea why it is lacking power?