2007 yamaha 90 two stroke water pump impeller

[bigcoaxum]

I just replaced my water pump on my 2007 yamaha 90 two stroke engine. the boat has been sitting for about 7-8 months. when i replaced the water pump and started the engine, it take about 2 minutes for the engine to produce the water stream out of the stream hole. the stream of water is not as fast as i think it should be and it sometimes gets weaker. I know the water should pour out of the stream hole at a constant rate but it is not. What could be the problem??? when i placed the impeller housing over the impeller, i turned the impeller blades counter clockwise. is this correct?? I also made sure the that the water line is free of degree. Please help. after several startups, i have the water shooting out at a constant stream but not with a lot of pressure behind it. I'm new to boats so I could be overreacting about this whole situation. any help would be appreciated. I have a video but do not know how to upload it to the site.

[robert graham]

Maybe remove/inspect/clean or replace the thermostat and pressure control valve located under that small square plate at top/back of powerhead(held on by four 10mm hex head bolts)....easy to do...You can clean these parts in a mild acid and toothbrush and replace if they're just stuck with deposits...

[bigcoaxum]

thanks Robert, do you have any pictures of this process??

[robert graham]

Just remove upper cowling, stand behind motor, look at near top of powerhead, see 4 hex bolts in a square pattern holding on a small aluminum plate....thermostat and pressure control valve plunger/spring/grommet is under that cover....carefully pry these items out for inspection/cleaning....not much to it. Sorry I don't have photos but doubtful you'll need them. These items and your water pump are all working parts of your cooling system...

[rodbolt17]

also drop the lower and reinstall the impeller correctly.
you MUST turn it clockwise when installing the housing.
if you turned it CCW its backwards and wont pump correctly.

[bigcoaxum]

also drop the lower and reinstall the impeller correctly.
you MUST turn it clockwise when installing the housing.
if you turned it CCW its backwards and wont pump correctly.

thanks Rodbolt17.

[bigcoaxum]

thanks Rodbolt17.

Rodbolt17, after watching a youtube video, you can see that this guy puts the impeller on counter clockwise. Can you tell me why this one goes on counter clockwise and not clockwise? is it because his engine is smaller, a 60HP 2 stroke?

I'm curious because I used this video as a guide. So mine should go on clockwise correct?

here is the video.......... https://www.youtube.com/watch?v=8PXb4nClFfc

[greasyshaft]

yes turn the driveshaft clockwise when pushing the housing down

[bigcoaxum]

wouldn't this be the same as turning the water pump housing counter clockwise if I'm turning the drive shaft clockwise? If so, mine should be installed correctly. there was no impeller on he shaft when I replace the water pump so that through me off.

[99yam40]

think about it this way, the motor turns clockwise looking at the top of flywheel when running.
So the drive shaft turns clockwise
You can turn the shaft clockwise when installing the housing or you can turn the housing cc with shaft not moving, it is the same thing

There should be an impeller on the shaft when installing the water pump housing, so not sure what you were trying to say.

Did you replace the cup and wear plate and all gaskets/o rings?

[bigcoaxum]

yes, that's what i did. I turned the housing counter clockwise without turning the shaft so i should be in good shape. what i meant about the impeller was that i purchased another lower unit and the lower unit didn't have a water pump kit on it. I installed the kit on it so i wasn't sure which way the impeller was suppose to be turned. Now that i know i turned the housing the correct way over the impeller, what should i try next? thermostat?????? the longer i let the engine run, the better the water flow out of the water flow spout but the water never had a full strong flow like i see on youtube on other engines. Keep in mind that i'm new to boating, this is my first boat and I inherited this vessel. How will i know if the water pump is working the exact way that it should be working.