[TexasRobert]

I just purchased a boat with a '95 Mercury 150 XR6 outboard (carborated). When I 1st start the engine, I do not see a steady stream of water being discharged from the engine and the engine smokes some until it gets warmed up. I am most concerned about the weak water stream though as I'm afraid it is not being adequately cooled. After the motor warms up, the stream seems to flow heavier. I replaced the impeller in hopes of solving the issue, but it is about the same as before replacement. Is this normal behavior for a Mercury outboard? I'm a former Yamaha outboard owner and they stream lots of water from the discharge...

Thanks!

[jdupree]

I have the same issue with my 1992 200 Mercury. It is normal for it to take a minute to "pee" when you crank it up because water has to circulate thru the block and t-stats before it will start to "pee". Mine also "pees" weak at idle but as soon as you give it some gas it "pees" really strong. Like you, I have replaced water pump, impeller, t-stats and it just doesn't pee that strong at idle.

This is my first Mercury like you, and from what I have been told the older model Mercs like ours don't "pee" very hard at idle because the discharge is regulated thru the t-stats.

If you have a water pressure guage, at idle should be around 5psi. If you are getting that you should be cooling fine.

[Silvertip]

Don't confuse a good tell tale stream as "cooling fine" because all that tells you is that the water pump is working. An engine can and will overheat due a bunch of other conditions unrelated to the tell tale stream.

[j_martin]

The only water available for the pee stream is what goes through the thermostats. Before the engine warms up, that is only 2 pinholes designed to let the air pocket escape from the top of the heads. At idle, much cooling water flows through other passages, so it does not get real hot, and the thermostats will open slightly, if at all.

If you get a real strong pee stream at idle something's wrong.
If you get a pee stream immediately on a cold engine, something's wrong.

Even at WOT, if in cold water, you might get a weak pee stream. That's normal.

hope it helps
John