I have a 95 Zr580, and I have had it in the 3 digits. up to last year anyway. It sounds as if you need a rebuild job. Do your self a favor and replace those crank seals. it took me a year of screwing with my machine and that is all it was. To really hook it up. I ported my cylinder ports, intake and exhaust, through some forged pistons in, took .010" off the head, replace the stock 40mm carbs with new 44mm, new nine tower primary and filled it with an EPI clutch kit, And yes I can hang with the basic single pipe 700's @ least the polaris and the V-max 700. off the line they are no problem