Merc pee hole pressure very weak at running temp.

[Liveliner]

<div>I guess I will list my engine concern as well. After the OMC pee problem I got concerned about my Mercury. I have an ‘02 150 Saltwater Merc with carbs. With a hose attached and in water I get the same results from the pee hole. No water until the temp gauge hits 140+. Then it only spit’s a broken stream. The water runs freely through the two lower small holes above the prop as soon as the engine starts. You can feel the water from the lower holes heat as the engine warms. My concern is whether or not I am pumping enough water up through the external water lines to the heads. The pee line is supplied from a tee in the waterline to the heads. While running I ran a piece of weed eater cord up through the pee hole to the tee. There was a very small amount of grit that came out but the line seemed clear. As the engine gets up to running temps the pee hole runs a steady flow but extremely weak pressure. It does not seem to squirt the water, it just sort of flows out.</div><div>My engine never seems to run hot even when I run it hard for several miles. Or at least I don’t think it does. I am not positive on how to read my temp gauge. It has the # 80 on the bottom and # 240 on top with a center mark that is # 140 There is a mark slightly below the 240 mark where my engine stays. It is the second mark down. I am assuming about 195 - 200 degrees is where My engine runs,</div><div>
</div><div>What is the plastic plug with the square head for that is located in the area of the pee hole? I am again assuming that it is an opening for flushing the engine. If so how do I go about flushing the engine. Running, not running, hot, cold, ???</div><div>I have ran my engine in saltwater, however after each and every use I run it hard in fresh water to flush out any and all saltwater. I do not think salt is my problem since I have friends who use their engines in saltwater and never in fresh water.</div>

 

[Auburnwes]

How long has it been since you replaced the impeller? Do you have a water pressure gauge?

 

[Liveliner]

Auburnwes - 10/14/2010 7:37 PM How long has it been since you replaced the impeller? Do you have a water pressure gauge?

</p>

I replaced the impeller a while back Like three years ago but it sat for about two years of that time. I would start the boat every couple months either with the hose or take to the ramp and let it run to full warm up. I would bet that there is less than thirty hours on the impeller. That is my thinking but was trying to rule out other things first. As i mentioned, My boat has never run too hot.</p>

Can someone tell me at what temp a Merc should run.</p>

 

[Liveliner]

I think I will install an Impeller kit after watching some videos.When I pull the foot do I have it in forward,neutralor reverse gear. On th e videos one guy says forward, one guy saysseparatein neutral but shift to reverse to reinstall.

 

[wrechin2]

That lower you can pull off in netrual. The old lowers and the in-line lowers will default to forward when you remove them and will mess you up. It is normal for it to pee when it reaches 143* or while you are running and it is below 143*. Start with a impeller is the smart thing to do.

To flush, install your water hose and turn it on with the engine off.

 

[trashtrout]

I have a 2000 mercury 2 stroke that would pee intermediately so I put a pump in and it didnt chaange.Blew out the line and finnaly found a little gravel that would wash over the peehole every now and then.

 

[wrechin2]

FIRST THING... You have never stated what your water pressure is. The lines you describe from the heads are where the 143* thermostats are. When they open at 143* that is when water passes and the engine starts to pee. ON the Tee you see a hose going to the adapter on the mid. When the RPM increases the volume of water being dumped into the mid will increase. This water will back in the adapter and it will pee from that even though the engine is not at 143*. So for the engine to pee constantly either the RPMS will have to be high or the engine has to be at a STEADY 143* or above. With the cooler temps, when the thermostats open, you are dropping the blocks tempature more than you were in July so it takes longer ot get to a steady temprature.


Maybe some trash in the line as trashtrout stated. Mercury recommends that the impeller be change once a year. They are like tires and will get memory and loose their ability to bounce back. This will change the amount of VOLUME that the pump can move. You stated that it has been 3 years so I would recommend doing that and it may cure your issue. Please note what I stated above about the adapter flooding and causing it to pee due to volume.

Your engine should run around 145 to 165 under normal conditions. It will run around 165* (maybe a little more) when fully warm idling and will drop to around 145-165* when running down the water due to the increase in volume of cooler water being circulated. This is not a car where the coolant in the radiator is around 40* cooler than the block. We have a whole lake of a lot colder water (coolant) than the engine is running. That is why the water is ran by the exhaust 2 times before it enters the cavity around the cylinders to keep it from causing the block from cracking from a huge difference in temps.

Just my .02 on the subject.

I have included the section out of the manual on the cooling system. This is for a 2002 but is the same as yours. The Hi-performance with the 1 peice adapter is totally different. Yours will have the 2 piece.

 

[wrechin2]

Here is the whole manual.... Look at section 4B

http://www.mediafire.com/?kmnndkwjjik