F225 Water Pump Issue

[miketv]

Every 100 hours, my 2002 Yamaha 225's are serviced. This includes rebuilding the waterpumps. I've always had a trusted mechanic do this for me. This time though, I decided to do the servicing myself. I have a horse trough that I fill with water to set the lower units in so they can pump water as if the boat was in the water. Before servicing, I checked both engines to see if I could find any obvious problems. Low and behold, the starboard engine is not peeing. I ran mono through the hole and found no obvious blockage. I then ordered the appropriate rebuild kits from Andy at SIM. I first rebuilt the Port engine so I could see what a working waterpump should look like. With the exception of a stubborn woodruff key, no big deal. I dropped the starboard lower unit and pulled the waterpump housing off. It was slightly warped where I could tell it overheated. There was also a build up of black rubber pieces (broken impeller chunks). After lifting the metal housing, I saw that the impeller had the ends broken off. I removed everything and cleaned all chunk of black rubber including the intake below. What makes this so suspect is that it is the second time the housing had to be replaced as the same procedure had to completed last service. I believe that the first time was my fault as I think I plugged up the intake in some murky water. However, this time, I know I had only clean water going into the intake. Could my mechanic have possibly not cleaned out all the chunks from the intake and it just took 100 hrs to really clog things up and heat up? The motor has peed everytime I've used it (except the test), though the steam seemed a little weak. No alarms at the console. Any suggestions why this has happened twice in a row?

[seahorse]

Do you flush the motor using the small hose and garden-hose fitting attached to the motor? If so, that is probably your cause. It is not made for running the motor.

[carbo]

You are filling your trough enough to cover the intake holes but those pumps will not always prime unless the water level is right up to them like when the boat is in the water. I have seem it multiple times with people not dropping them all the way in the water on a boatlift.....when the housings melt and impellers heat until brittle it is pretty obvious they didn't prime. Get the water level up during your flushing procedure.

[oldredfish]

This sound like something is stopped up or a little stopped up. I have never had this problem and I have run outboard for a long time. You need to check your water flow passages. Also add some lube when installing impeller.

[FX10]

Originally Posted by oldredfish

This sound like something is stopped up or a little stopped up. I have never had this problem and I have run outboard for a long time. You need to check your water flow passages. Also add some lube when installing impeller.

I would definitely invest in water pressure gauges for the motors. It's a good way to see if your not pumping enough. A water pump should last around 400 hours. Although most people do it every season, like my self. And I don't even put 100 hours on it.

[marty-10]

I learned over the weekend that the motor needs to be in the water as if you were launching the boat.
We tried every thing to get enough water to get it to pee but only ever got a trickle. Finally I said the hell with it lets go back down the ramp and it pissed like it had been drinking all day.