OK, so I have a '95 Rinker 265 V with a 5.7l block on board and a Bravo 2 stern drive. It is moored on the river Thames where we have a speed limit of 8knots (don't laugh!) in the non-tidal reach (below the last lock at Teddington, it is considered tidal, and the speed limit is higher). The big block is clearly over the top for power and barely gets over 1,000 rpm here. So I am a bit concerned about the plugs fowling up and the engine not benefitting from the odd power surge (for which it is clearly designed). Speaking to another boat owner, they suggested putting on a smaller prop, or one with a different pitch, so that the engine worked harder. Does anyone see a flaw in this?