Hi,
It's my first post here. I'd sure appreciate some help. I bought a Duck Hunting boat with a mid/ late '80's 40HP Yamaha outboard on it. The motor is from South Florida, and is well used, and shows obvious saltwater use. When I bought it, I knew it had a water flow issue, but I felt like it was well compensated for in the price. Now I'm not sure.
When I first got it, the boat started and ran well on the muffs. But it had no pisser flow out on the water. A mechanic replaced the water pump with an oem kit, using all the new parts/ gaskets. Pissed like crazy for the first 20 minutes or so, then slowly loses flow to the point where there's nothing at idle or at speed within the first hour or so.
So I had the mechanic replace the upper plastic housing along with a whole new kit, cuz the housing looked old. Also replaced exhaust manifold gaskets too. Same thing. Good flow at first, tapering to zero within the first hour. Had went through a slough, and he was convinced that maybe some mud had quickly worn out the impeller.
This time I did the job. Old impeller looked fine, but replaced it with whole new kit anyway. Same results. Strong flow, then tapers to none. The motor pisses like crazy still on the muffs, but won't do it on the water. I'm stumped. I'm thinking about asking my doctor about Flomax..lol.
Last couple times, I thought it was fixed, and went Hunting. Due to circumstances, had to drive it w/o pisser flow for a few miles. Funny thing was, it ran great each time, and didn't seem to overheat. It was pretty chilly out (N. IL. winter) but I still am surprised it ran. It actually starts and runs really well.
Can anyone help me? Thanks.
Shawn
It's my first post here. I'd sure appreciate some help. I bought a Duck Hunting boat with a mid/ late '80's 40HP Yamaha outboard on it. The motor is from South Florida, and is well used, and shows obvious saltwater use. When I bought it, I knew it had a water flow issue, but I felt like it was well compensated for in the price. Now I'm not sure.
When I first got it, the boat started and ran well on the muffs. But it had no pisser flow out on the water. A mechanic replaced the water pump with an oem kit, using all the new parts/ gaskets. Pissed like crazy for the first 20 minutes or so, then slowly loses flow to the point where there's nothing at idle or at speed within the first hour or so.
So I had the mechanic replace the upper plastic housing along with a whole new kit, cuz the housing looked old. Also replaced exhaust manifold gaskets too. Same thing. Good flow at first, tapering to zero within the first hour. Had went through a slough, and he was convinced that maybe some mud had quickly worn out the impeller.
This time I did the job. Old impeller looked fine, but replaced it with whole new kit anyway. Same results. Strong flow, then tapers to none. The motor pisses like crazy still on the muffs, but won't do it on the water. I'm stumped. I'm thinking about asking my doctor about Flomax..lol.
Last couple times, I thought it was fixed, and went Hunting. Due to circumstances, had to drive it w/o pisser flow for a few miles. Funny thing was, it ran great each time, and didn't seem to overheat. It was pretty chilly out (N. IL. winter) but I still am surprised it ran. It actually starts and runs really well.
Can anyone help me? Thanks.
Shawn