I have a 1988 ranger boat with a 50 hp yamaha outboard. I have been very fortunate so far and the water pump has held strong. I noticed the other day that it was getting a little weak though. I have a tournement next saturday and need to get this fixed. my question here is can anyone tell me what all is required to change the pump or impellor. also is it a job to to at home or is cost beneficial to have it done. what are the cost both ways. thanks for your time

I've only experience with Suzuki and older 'Rudes, but it was easy enough on those.  Drop the lower unit, remove the pump housing, slide the old impeller off, slide the new one on, bolt the housing on, grease it up and reinstall the LU.

Well worth doing yourself if you are mechanically inclined.

thanks for the help, i did it myself this morning. hardly any problems, just the shift linkage adjustment but i think i have that now. going to take it out later tonight.