Yamaha F90 Impeller / Water Pump System Leaking?

[pckeen]

I replaced the impeller in my 2010 (manufactured) Yamaha F90. When I removed the lower unit, I didn't disconnect the small rubber hose, so it stretched and pulled off. I inspected it, but it seemed fine. When I reinstalled the lower unit and ran it, water was running out of the pee hole just fine, but I also noticed water coming out of two places on the lower unit. I reconnected the hose with a new clamp.

I've replaced gear oil in lower units many times, but this is the first time I've replaced the impeller on this motor - so I was paying more attention to the lower unit when running it on muffs than I have before. Not sure if this is normal or not - can you let me know? Here's a video showing where the water is coming out of the lower unit.

What does that rubber hose do anyway?

 

[CadoTx]

The small black rubber tube should be for your speed odometer. It appears that the tube that goes from your water pump to the engine is leaking water into the shaft case or midsection. When you pulled the lower unit, did the water tube stay attached to the water pump on the lower unit or did it stay inside the midsection? The bushing on the top end of the water tube may have developed a leak due to the increased water pressure of the new impeller and needs to be replaced. Does the water coming from the lower unit and tale tell (pee hole) increased or stay the same when the engine speed is increased? Are you getting water in the lower unit oil?

 

[doubler1950]

I'm having the same problem with my motor. It does fine peeing in the lake but with muffs water comes out a lot of places.

 

[pckeen]

The small black rubber tube should be for your speed odometer. It appears that the tube that goes from your water pump to the engine is leaking water into the shaft case or midsection. When you pulled the lower unit, did the water tube stay attached to the water pump on the lower unit or did it stay inside the midsection? The bushing on the top end of the water tube may have developed a leak due to the increased water pressure of the new impeller and needs to be replaced. Does the water coming from the lower unit and tale tell (pee hole) increased or stay the same when the engine speed is increased? Are you getting water in the lower unit oil?

The tube stayed inside the mid-section. The old impeller was still in perfectly good condition (I was doing this replacement as a caution). I did not see any sign of water in the lower unit oil.