I had a new impellor installed on my 02 xr6 a couple of weeks ago. I took it out for the first time since this past weekend. It still pumps out water at a good steady stream when I am cruising across the lake but like when I slow down to a very low speed or an Idle it really slows down alot. This is what it was doing when I decided to take it to a marine shop. I don't think any of the intake ports or clogged up. Is their a true water pump on the engine somewhere. And if yes where is it located? Also the hot alarm did not go off this past weekend and I know it works. Thanks for any advice or suggestions.

Do you have a pressure gauge? You should.

The tell tale (pee hole) is easily clogged with mud and stuff, just pull it out of the outlet and run a wire up it, sure you'll find some muck in there that's halting it.

From my experience engines are like Goldilocks...they have to be just the right temperature...not too hot and not too cold. At low speeds, the thermostats control the water cooling the engine. When it first starts, the thermostats are closed, but as the engine warms up, the thermostats open. At higher RPMs, the water cooling the engine is controlled by the poppet valve. The thermostats can be easily tested with a string and hot water. That being said, they are pretty cheap and easy to replace. The poppet valve is a little more involved, but still fairly straightforward. The steady stream you see at WOT is from the poppet valve opening wide and sounds fine. As for the slower flow at idle, as long as you aren't hearing an audible alarm, you should be OK. The high temperature alarm will be a loud, continuous BEEEEEEEEP (assuming your high heat alarm is functioning). For what its worth, my 98 Merc 150 does the same thing.

I have the same boat in an 03. It does the same thing. When I inquired about it, the mechanic told me what Aggie Dave said. When I first start it, it just kinda spits, once it warms up its steady.

Same thing here. My XR6 2003 put a good water stream out of the pisser when up and running with good water pressure. Then when I come off of plane and start to idle my water pressure gauge is showing good water pressure but the pisser will take some time to get a good stream coming out of it.

With a new water pump in gear and ideling up, the water pressure will climb to about 10 or 12 psi. Then the poppit valve will open and the pressure will fall to about 6 or 8 psi until the boats gets moving good and the pressure will get to about 15 to 18 psi at full throtle.

I also added high speed scoops on my water intakes and that made a real difference in my water pressure. I can get 5 more psi with the scoops.