first i would like to say i'm a noob so flame away.so i bought a 1998 zr 600 with a blown piston on the pto side. i bought a new piston and did a light hone job on the jug(yes i know now that it is plated and plan on doing a complete and proper rebuild just wanted to give her a run first ) so she fired right up and ran like a champ to my surprise. i took it for a slow rip around the field, but as i was coming back it started to bog and my friend said he saw sparks coming from the exhaust. so my plan is to do the rebuild now, but my question is as i was going to tear it apart i noticed the fuel pump is not hooked up but it ran like a top :dunno: . every sled i have had would not run without a pump why is this one running good without it?