I need some help. I just bought a 1984 IMP<br />18',open bow,3.0 4cyl engine OMC.<br />How fast could it GO. I got 2 props with it,<br />one of them is damaged, 13 3/4 15p.<br />When riding it top speed RPMs is at 40,<br />Speedometer does'nt work.<br /> please help, to answer some questions...