I have a 1991 26ft Regal w a 454 7.4L Mericruiser that i just picked up about a month ago. Ran it hard 2 weekends in a row and on the 3rd week, when I open it up to get up on plane, the rpm's drop REALLY FAST back down to 1800-1900. It keeps doing this. If I rev it slow I can get the rpm's up to...