The main problem I have seen are the ever changing EPA guidelines put on the manufacturer's; whether Merc., OMC, Bombardier, Yamaha, Suzuki, etc...If you think the prices are high, there are reasons. An engine is designed, parts are cast, tooling, etc.. to produce a complete line of engines only to have to change the specs every couple of years.(See C.A.R.B.) To keep from having to go back to the drawing board the mfg.'s have to make adaptations to the current production for cost and efficiency. Imagine how expensive it would be if the initial engineering of the motor changed each time a new guideline is imposed. (New castings, tooling, etc.) Whether cars, boats, engines, or motors, the biggest price hit is in the manufacturing. Many mfg.'s try to build new models with some foresight of the changing reg.'s on the horizon, however an engine built for specific tolerances can only be "tweeked" so much before the failure rate goes up. I would rather the feds look at more obvious violators such as commercial diesels (sorry Scott!), JP40, and large scale manufacturing. I can't believe our boats and lawn mowers do more damage than the more obvious, however more influential, previously listed examples. Just my .02!
P.S. Back to the original post. The Mercury support crews have been advising for the past couple of years that we run the Opti's between 2500 and 3000 rpm's to clean off the plugs and blow out the carbon. A short occasional five minute run in that rpm range will extend the life of the plugs and reduce the carbon build up. It's a good idea for all the 3 litre blocks, regardless of mfg.
