I recently changed out the water pump in my 2008 40 HP Yamaha 4-stroke tiller. I put it in a tank of water and it ran water out of the "pisser" on the carb side at all times. A half hour or so later I looked back at the motor while I was in the water and it wasint "pissing" out of the little water tube. Instead it was dripping out of the hole directly in back of the outboard around the mid-section just below the exaust(I believe it's the exaust). It ran fine for miles and miles and I felt the water coming out of the hole in the back and it was pretty warm. So why is the water not coming out of the little "pisser" tube on the carb side and why is it just coming out of the hole in the back. A little bit is spraying out of bigger penny sized hole above it. Thanks and I hope someone here can help because I've tried calling Yamaha techs and they can't seem to help me out.
Edit: Im not getting an overtemp light/buzzer and it seems to be running just fine if not a little warm. How warm should the water be coming out of the engine?
Re: 2008 40HP Yamaha 4 Stroke; Water Pump Problem?
You can remove that hose from the little fitting on the cylinder head and check for it being plugged up with bugs or dirt, run a wire down in it. Mud wasps love to build nests in mine. The hose is just an indicator of water flow through the motor, but not really a part of the cooling system, other than that. Good Luck!