I occasionally have that problem with my 200 hp 2002 Bombadier. I don't know if Yamaha technology for cooling is similar. In my case, the powerpack gets hot to the touch. I trace the hose from the top of this down to the vapor separator, disconnect it there, discover the crud in the intake tube, poke it out, and am good to go again. (You can tell when the job is successful, if you can now run your thumb along the top of the powerpack while motor is running and not feel any significant heat. Good luck!