Re: 2003 Yamaha 200hp Vmax HPDI cons & pros
You know it is hard to really tell what the problems actually are from motor to motor. Getting advice varies from whom you talk to. It's like people who try to discuss props and try to decide which prop is the best. They may try out this new prop and have better performance from weather conditions and think that their prop made all of the difference in the world. When the best prop is to stick with the manufacture's prop, the one that is R&D'd and had that taken into consideration for that particular product. The fact that everyone of the DFI's are good, it is just of matter of preference. Yamaha has a history of bullet proof electronics, however when it comes to the oil injection process they have decided to stick with their tride and true oil pump. Both the Optimax and Etec use solenoid oil injection. Another is fuel delivery. The HPDI can inject fuel close to 1025psi, the optimax a combination of air and fuel delivery of 90psi (depending on model), and the Etec uses a high pressure solenoid that can achieve pressures of 500-600psi. Now a salesman can try to sell you on all of the benefits of each product. But all of this means Jack Squat unless the engine is properly rigged. I like Yamaha the best, their HPDI is good, is it the best, probably not, is it the most reliable I would say yes. But here is the thing, the boating market is sketchy at best. Their is no certifications of standards other than really boating safety. The NNMA sets these standards along with the Coast Guard. So they may buy their fuel tanks from one manufacturer and switch the next week go to another company. Why is this fact important? As of right now most of all manufactures fuel pumps are on the engine. Auto manufacturers put their fuel pump in the fuel tank. What I am trying to get you to see is that boats draw vacuum, and cars push pressure. I know I am rambling a little bit but this is important. If you remember watching Bill Nye the science guy/Mr. Wizard, you probably saw the episode where he applied vacuum to water is a closed compartment and made it boil. Well this is essentially vapor lock or fuel restriction. All of these things need to be checked. So before you decide on which model remember that the engine is only as good as what it is pushing.
