I was woundering if anybody has any information on the 99-00 Z sno pro fan cooled as to how much horse power and what the top speed is for a stock sled

My sled is getting about 3 mpg and has no throttle response the compression is 120 psi and has a new coil. I have been told two different things one said that the fuel injectors are bad and the other said the fuel pressure regulator was no good. has anybody had the same problem please help me out!!