I bought a new Ranger 185VX with a Yamaha 150 VMAX HPDI in 2005. For the past 3 years this has happened: When I first get on the water and warm up the engine, I get on plane easily as the RPMs shoot up to 4000 immediately. However, as the day goes by I frequently have trouble getting on plane. I will put the hammer down, but the engine only gets up to 3200-3500 RPMs and the nose stays up. The problem is not weeds because I always check for weeds. What I have to do is floor the throttle in reverse several times. The first one or two times the RPMs stay low. After 3 or 4 times in reverse the engine will rev up properly, then I can put it forward and get on plane easily.

My state has E10 gas, but I always put marine Stabil in the tank before I put gas in.

Any help or suggestions would be most appreciated.

Mike