My waverunner will crank and idle, but when I put it in the water and try to pull the throttle, it bogs down and shuts off. I pulled it out of the water, cranked it, pulled the throttle and it reaches max RPM. Doesn't do that in the water. What could be causing this?

Chris, September 2009

I just replaced the spark plugs. One was really bad, the prong was bent all the way to the post. My prediction, it wasn't firing and the piston kept knocking it and bending it because there was no combustion to compress the piston back. Waverunner running on one piston=reduced HP which is probably why it was bogging down and shutting off. The engine wasn't powerful enough to push adequate water through the jet. I haven't put it in the water yet to see if this worked, but I will this weekend.

Chris, September 2009