HAVE A 1998 370 THAT WAS REPOWERED FROM 370hp TO 420 hp 8.1 HO'S. LOOKING FOR HELP ON CRUISE PERFORMANCE SINCE 3500 RPM IS NOT GOOD CRUISE SPEED AND 3100 IS NOT BETTER AND I DO NOT HAVE FLOW METERS.
prior owner replaced 370 HP mercs with 8.1 HO 420HP mercs on a 1998 370 Sundancer. 3500 rpm is not the place to be with the 420's for fuel efficiency but do not have fuel flow meters. Looking for an efficient RPM.
have a 1998 370 sundancer that was repowered from 370 HP to 8.1HO 420 HP Mercruisers by the dealer for the bank. While 3500RPM seems to be the touted as efficient cruise speed for the 370HP it is certainly NOT the case for the 420HP. Any tests results or info on efficient cruise speed as the...