Cooling water flow on '95 9.9 outboard

Good evening. I've done a search and didn't see anything that would help.

I have '95 9.9 that has a minor issue of constipation with regards to the cooling water flow. When the motor starts, the water sputters out the pee hole, then becomes strong, forceful flow, then peters out to a trickle. The whole unit was serviced some time ago for the same issue, but seems to have resurfaced.

Here is what I am seeing. When I back flush by connect a hose to the fuel pump (last thing in the water pee hole chain) I see water coming out of the upper unit release valve, the water intake in the lower unit and the propeller shaft area. The water exiting the prop shaft wasn't too much.

Today before taking the boat over to the boatyard for a bottom paint, I played with the motor. I was back flushing again and decided to put the motor in the water and give it a crank or two. I have a switch so the motor would not start. I pulled the motor out and noticed a better exit of back water. So I reconnect the hoses, put the motor in the water and started it. Immediately the pee hole was shooting a solid stream of water. This stream never really faltered, but it did have some changes, but was still strong.

So I am thinking there may be a blockage, ever so small, in the lower unit. Would be nice if I had a flow chart of the cooling system. Anyone have one of these or know where I might be able to get one? There is nothing in my repair manual other than water pump info.

Thanks
Brian D

[boats.net]

You can get the service manual at www.yamaha-motor.com but it doesn't have a flow chart for cooling system. The water pump pumps water to engine by way of a pipe, the pipe does have a rubber grommet on top that may be bad but you would have to remove engine to get to it.

The pee hole is for monitoring the flow of water. Is that a correct statement? and if the pee hole water flow is sporadic then there is something preventing cooling water from flowing correctly. At least that is what I was told. So if the pee hole is for monitoring, where exactly does the water exit. I know it enters in the lower unit.

Thanks

[boats.net]

The pee hose is just an indicator and doesn't affect the cooling of engine, just let you water pump is working. The water exits engine through exhaust housing and out through prop. If the engine is not overheating then probably is getting enough water.

Thanks, that was also my understanding but never had it confirmed. I will be putting the boat back in the water tomorrow. Need to figure out what's causing the slight constipation. We'll figure it out sooner or later. Thanks again.