Yamaha Water Pump Problems

[artherm]

I have a friend with a Rinker I/O 24 ft. that I am trying to help. He doesn't have a computer. His boat has the Yamaha outdrive, with a GM V-6 engine. I think they call it the 4.3 litre. He has to rebuild the lower belt driven water pump almost every season. I guess this would be the primer pump to the main engine water pump. The new impeller kit is readily available, but just seems a hassle to have to do it. Boat is fresh water lake driven, no sand, and receives routine maintenance. Is this just a common occurance maybe with dry starting this engine?

 

[Don S]

Re: Yamaha Water Pump Problems

That is the raw water pump. Many people replace the impeller yearly as a preventative maintenance measure. The pump should never be run dry. The impeller can be ruined in as little as 15 seconds when dry. Many starts of only a few seconds will overheat the pumps impeller and cause it to take a set and loose it's ability to pump in a very short time.<br />If he wants to start the engine to make sure it runs before heading for the water, get some muffs for the drive and run it on a water hose.<br />An impeller should last 2 years with no problem and shouldn't NEED to be replaced yearly.

 

[DJ]

Re: Yamaha Water Pump Problems

Is this just a common occurance maybe with dry starting this engine? <br />--------------------------------------------------------------------------------<br />

There's the problem.

 

[artherm]

Re: Yamaha Water Pump Problems

I guess I was misunderstood when I said he was dry starting the engine. What I meant to imply was, with the boat in the water, it would be this pumps responsibility to start the water flow from the intake to the engines main water pump. I would have to think that there would be times when there would be very little water/coolant at the pump at start up to lubricate the pump and reduce wear.

 

[Capt Ken]

Re: Yamaha Water Pump Problems

Common problem with the Yamaha setup. With the pump mounted on the front of the engine, it may take awhile for the pump to pick up prime. If the pump has some wear/age on it, then that also causes problems picking up prime. On the Yamaha, on startup, the engine should be rev'ed a couple of time to help pick up prime. The pump needs to be dissembled and checked for wear. If the carbon bearing in the rear housing is worn or grooves found in the housing, the pump needs to be replaced. What ever you do, do not damage the pully. There is no more in existance. They come only on new pumps and they are getting few and far between. I bought all that one supplier had a couple of years ago and down one left on the shelf. They are a Sherwood R991 pump that was built for Yamaha.