Well I figure ill start a new thread rather than bringing an old one back. If you don't remember my hpdi is having problems starting on the water. It starts fine on the hose but wont start on the water. It is also not reaching wot rpms. I eventually brought the boat in to another, more reputable Yamaha tech. After a week in the shop he thinks he narrowed it down to something between the power head and lower unit. When in his test tank the motor wont start. When he removes the lower unit it does. He put another lower unit on just to make sure mine isn't the problem. It does the same thing. His theory is something is blocking the exhaust and creating too much back pressure. This would also cause my low rpms at wot. This is all going back to when the motor was rebuilt. It hasn't been right since. What do you guys think? Does it sound like he is on the right track? Is this a plausible diagnosis? He should be pulling the powerhead any day now and then I should know more.
