I bought a 1997 zx7 back in february as a project bike. Bike runs good but I believe is too rich. I am getting about 100 miles out of a set of plugs before they foul out. Have taken it to shop to have leaned out. Mechanic stated there was no fuel pump on bike and that carbs were gravity fed, which might be part of the problem. Bike has full muzzy exhaust with k&n filter.