I recently purchased a 1990 256V with a 70 HP Johnson. It currently has a 14 X 17 prop on it but i am not sure what the original size was. It is only running about 34 MPH and seems like it should be more. The engine runs great so thats not the problem. The RPM gauge is not working (hope to get fixed soon) so i dont know what RPMs i am running. Gotta replace the fuse block or clean it because of the rust so hope that fixes it. What speeds should i expect and does anyone know what the original Prop size was. Thanks in advance!!