50 hp. yamaha water pump question

[jessekib]

Ok. this weekend i took my boat out to the lake, there was a bunch of duckweed a good solid 40 feet from the launch out. i had my boat idling for a while right there in that and then took off about 5 min after i took off i looked back at the motor and my pump wasn't pissing. I killed it and cranked it again then opened it up and it started pissing again, great. then i go back to the launch and let my boat idle while i was getting my truck "like an idiot " and now it aint pumping hard at all just kinda barly pumps even off the muffs. Is there an easy way to fix or flush this or should i change the water pump. how easy is it to change? where is it even at? Any links or pics or comments would be a big help. Thanks!<br /><br />Oh. it is a 1991 40hp. converted to a 50 if that helps.

 

[Dr Jizm]

Re: 50 hp. yamaha water pump question

sounds like a high pressure flush would help, or even back flushing.

 

[bigbrownbuku]

Re: 50 hp. yamaha water pump question

the pump is mounted to the top of the gearbox. if you have any concerns that it may have run without water service it.<br />first try some compressed air through the telltale at the cowl and where the hose attaches the block. could just be salt/corrosion blocking the pipe.<br /><br /> http://www.yamaha-motor.com/outboard/parts/home.aspx <br />go here for a very good picture of where the pump is and how it goes together.

 

[jessekib]

Re: 50 hp. yamaha water pump question

How do i back flush it? and by high pressure you mean the hose all the way high on the muffs? I found the water pump on that link and wow...i don't think that i could do that on my own i will try to flush it out with air or water before taking it to my mechenic. Thanks.