Intermittent "stream" on 90hp merc

[mr wizard]

I noticed that the waterpump "stream" flow was decreasing and becoming intermittent on my 2001 90 hp merc. I changed the water pump impellor and still have the same problem. What else could be the cause?

[andy j]

This is a indicator,it shows that the waterpump is doing its job(cooling the motor) I have had mine slow down to not even much of a stream and I took off the hose and cleaned it out and it has been fine ever since. I hope that it is as easy a fix for you as it was for me. Good Luck

[mr wizard]

Thanks, I'll try that tonight. What was blocking your hose/tube?

[ChuckN]

I'm not positive about your motor, but my Merc does the same thing. The thermostat controlls the stream on mine. I thought there was something wrong, so I changed the thermostats and the water impeller. It's normal for my engine.

I have had debris plug up the stream hose too, at the fitting the hose connects to. They come off easily for inspection/cleaning.

[Giant_Jackpot]

I had a snail about the size of a pin head block mine last year. You never know……….

[Dragonsm]

I encountered this issue last year on my 50 hp Evinrude. The impeller was in need of being changed. Some of the impeller was actually missing. Didn't think much of it. However, those pieces work their way through the motor and "flush" out of the tell-tale. (or at least that is what I call it) A little chunk was blocking the flow of water out, and the motor wasn't cooling properly. I took it to a local guy since I was very uneasy about it, and now my motor "pees" with the best of them.

Just a thought, if your impeller didn't come out in one piece...there may be a part of it lodged someplace in the motor.

[mr wizard]

The impellor "looked" ok but there was some very small black specks in the housing. I will be cleaning out those tubes tonight. Thanks for the help guys.

[waterwolff]

I also had the same problem and found pond seed blocking the discharge tube at i'ts outlet

[korn_fish]

Yeah, there is a thermostat on the mercs that regulates the stream flow. Mine is a 20 horse. Freaked me out the first time I had the motor. When in really cold water, the stream will only run occasionaly. In the head of summer though, you will see it run non-stop.