Motorcycle Repair: 1991 zx6, market pipes, straight pipes

Question
I have a 91 zx6 with stock exhaust. I was wondering if it would hurt the motor if I took the mufflers off and ran with straight pipes?

Answer
Yes It can hurt the performance as well as the engine. The exhaust has to have some back pressure in the flow to work right. If you are going to drive this on the highway you take a chance of getting a ticket for noisey exhaust. Most after market pipes may be bigger in diameter to get the exhaust to flow easier but the muffler causes a sonic pulse in the exhaust to force the hot gas mixture to bounce back toward the exhaust port then back to the pipe and out. This action creates a scavaging effect on the heads causing them to run cooler and burn cleaner.