When our 15 Yamaha 2 stroke was stolen we replaced it with a 9.8 2 stroke Tohatsu. Although not as well made as the Yamaha it's a peppy engine that is really light. The engine is about 2 years old and almost from the beginning it had a,,,,,, situation. When the engine is cold or hasn't been started for a couple of hours you can hit the throttle from an idle and off it goes,,,,, jumps out of the water and up o a plane. Once it warms up and you try to do the same thing the engine struggles to get to a plane. It's like the 9.8 just turned into a 7. I went through everything I can think of to correct it but haven't found the cause.

We've got the 9.8 Tohatsu on a 9.5' AB heavy weight RIB. Total weight of the boat, 2 of us and gear is about 550 LBS not including the engine (47 LBS)

Any suggestions?