Slow to plane

[bob.roebuck]

2006 Yamaha sr230 jet boat . When I first start the boat it won't get up on plane , no speed. The RPM'S are up but the boat won't go fast. After about 10 minutes of running slow and trying to get up on plane it well finally run and runs great the rest of the time until it sits awhile and cools down and then it is the same thing all over again . Help!!

[boats.net]

Well the RPM's up but no movement would lead me to believe that the impeller and wear ring needs replace. But this would be evident at all times.