Hii , i'm new to this forum , i bought a 97 zxi 750 jet sky last year i rebuild the top end new .50 oversize pistons kit put it together comp test 150 psi each cylinder, i did a leak down test and is perfect, but my problem is that is not producing any vacuum for the fuel pump instead is blowing air , the reed valves look good, any ideas this thing is kicking my ***. thanks