-What performance mods can you get for the Yamaha Jet Boats? Is there an equivilent PWC engine I can use for performance parts?
-What is the top speed of these boats?
-Why does the F-N-R shifter vibrate so bad when full throttle is applied?
-My right engine wont rev past 3800 RPM and runs very rough for the first 10 minutes everytime I take it out. After 10 minutes it runs fine for the rest of the day. What could this be?

The boat is a 2003 LX210 and just wanted an idea before I take it back to the dealer. Thanks.