Yamaha 4.3 Water impeller

[patmeat]

How difficult is it to change the impeller in this pump? I foolishly ran it dry. I already ordered a replacement after I tested it with muffs. It pumped no water.

 

[xxTheJokerxx]

Re: Yamaha 4.3 Water impeller

I'm far from an expert on the matter, but I changed mine in about an hour and a half. The hardest part was taking the water pump off of the block because the bolts hit the pulley when you back them out, so I had to loosen both of them at the same time. I can't speak for the 4.3 but I'm sure it's similar to my 5.7L. There are 2 bolts holding the pump to the block and 2 hoses. One hose goes to the transom housing of the outdrive and one to the GM-style circulating pump on the block. Once the pump is off, there are 3 3/8" bolts holding the rear plate on the pump. When you get the plate off the impeller (in my case) slid right off the shaft. I cleaned the inside with emery cloth, coated everything with lubriplate for the initial dry-start, and had it running in less than 2 hours.

 

[patmeat]

Re: Yamaha 4.3 Water impeller

Thanks. I'm lucky to have a manual. I have already ordered replacement impellers(2) and am pulling the pump off tomorrow.

 

[xxTheJokerxx]

Re: Yamaha 4.3 Water impeller

I'm just glad you found it with muffs on it...mine pumped a little water at first and my unfimilarity with the Yamaha drive led me to believe it might be working well enough. About 200 feet from the boat ramp it began overheating and I had to be embarassingly towed back on what was supposed to be the boat's maiden voyage.

 

[Capt Ken]

Re: Yamaha 4.3 Water impeller

You removed the wrong bolts Joker. There is two holes in the pully. align the holes with the bolts holding the pump to the bracket and remove the bolts. The pump will drop down allowing the hoses to be removed.

 

[patmeat]

Re: Yamaha 4.3 Water impeller

Impeller was trashed. I'm replacing it as soon as Capt. Ken can get me one or two.