View Full Version : yamaha ProV getting hot at WOT and one bank warmer than the other

08-04-2009, 09:47 AM
Picked up some sand in the bottom end when parking the boat at a friends place. Replaced the impeller and have normal water pressure. 8lbs at idle and 15 once on plane. Runs good and cool at idle and mid range speeds. Alarm goes off when running above 5000 RPM and one head (starboard) side is warmer then the port side. I am thinking stuck thermostat or jammed poppet valve. It is a 1992 Yamaha Pro V. Does this engine have just one poppet valve?

Any input would be appreciated

08-04-2009, 09:53 AM
Had the same thing happen to my friends yami, sounds like thermostats

08-10-2009, 03:18 PM
Had some sand in the thermostats and one of them was ripped. Put in two new thermostats and cleaned out the poppet and we are good to go.