Water pump Flow on Merc. Black Max 150

rowland

Recruit
Joined
Sep 6, 2003
Messages
2
This boat and motor are new to us. '92 Bayliner Trophy with '92 Merc. Black Max 150 O/B. From the time you start a cold motor till it pumps out a steady stream of cooling water is about 2-3 minutes. There is a slight spray when initially started but the steady spray takes 2-3 minutes. Is this normal for this motor? <br /><br />Is there a way to hook up a temp guage to this motor? There is no reference to this in the operations guide. Alarms are ok but a guage is the only way to go.<br /><br />Thank you for the help.
 

andrewkafp

Lieutenant Commander
Joined
Mar 15, 2003
Messages
1,668
Re: Water pump Flow on Merc. Black Max 150

Seems quite a long time. My 50Hp takes about 30-40 seconds. But your 150 is a big motor with quite a large volume of water that needs to fill up before exiting. How is the pressure from the tell tale when it finally gets going ? And after 10 min of running, how hot is the water ?
 

greasemonkeyozi

Petty Officer 1st Class
Joined
Jul 16, 2003
Messages
282
Re: Water pump Flow on Merc. Black Max 150

It shouldnt take that long for it to rush out, but atleast its spitting something out.
 

ZmOz

Captain
Joined
Aug 13, 2003
Messages
3,949
Re: Water pump Flow on Merc. Black Max 150

My 150 only takes like 20-30 seconds.
 

andrewkafp

Lieutenant Commander
Joined
Mar 15, 2003
Messages
1,668
Re: Water pump Flow on Merc. Black Max 150

Sounds like some blades may be broken off impeller, reducing pressure. When was the last time water pump was done ?
 

marinegrh

Petty Officer 2nd Class
Joined
Sep 1, 2003
Messages
196
Re: Water pump Flow on Merc. Black Max 150

ahhh water pumps, first tell tale of low output is the time it takes to pee, should be replaced every year or 100 hours whichever comes first, why, cupping and wear, some people do others dont, the ones who dont you read about in the powerhead failure sections, if you dont know when it was done when you purchased the boat, might be a good time to have it changed, if your a do it yourselfer, its not to hard to do, i suggest buy a service manual from seloc or clymer, it will give you step by step info, along with the pump thermostats are also in the picture, they keep the engine at proper temps when working correctly and not all clogged up, some owners just change impellers, some do the entire pump assembly, its your choice, but for a little extra money why not do it all, if you need part numbers feel free to shoot me a e-mail, at marinegrh@bellsouth.net include your engine model and serial numbers<br /><br />good luck
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
15,413
Re: Water pump Flow on Merc. Black Max 150

I've got a 175 of the same vintage and it acts the same way. The motor circulates water through the block and dumps it out the prop until the motor is good and warm. You will not get a steady stream out the pisser until the motor is completely warmed up and the thermostat on the heads opens. In the spring when the water is still cold, the thermostats on mine never fully open and all I get is dribble all day long. Instead of the temp gauge would recommend a water pressure gauge.
 

paulgp6022

Petty Officer 1st Class
Joined
Jul 27, 2002
Messages
288
Re: Water pump Flow on Merc. Black Max 150

I always look at other boats telltales while going through no wake zones/marinas at low speeds. You would be surprised at how many have a poor stream coming out. Some older motors trickle out barely! I think the number of boaters that know about their impeller and it's needs is relatively low (at least in my area).
 

gss036

Commander
Joined
Jan 18, 2003
Messages
2,914
Re: Water pump Flow on Merc. Black Max 150

Sounds normal to me, I have been running a 1989 200hp merc since new and it I just had my pump and head gaskets changed and it does the same thing. I would look into the time since the last change. If you run saltwater, every 3rd year is MAX time to change out the gaskets & impeller. When you someone with a Marec and it runs like water water faucet, most likey they are running without thermostats.
 

KCLOST

Commander
Joined
Jun 22, 2002
Messages
2,095
Re: Water pump Flow on Merc. Black Max 150

Rowland,<br />This is totally normal.... The last three replies are right on the money.... I have an 86' Merc 175, and the same thing happens. The stats don't open until the block temp. reaches 140-145 degrees... Only then will you see a full stream of water and it still may not be steady, it may surge even at moderate rpms... You are dealing with a High pressure water pump, with thermostats and a poppet valve (which only opens at High RPM's).. With all those variables the odds of constantly having a steady stream of water at all RPM's are slim to none...<br />I would suggest hooking up a temp gauge however, the sender for the gauge should be located under the number 2 cylinder (port side/left side under the top spark plug). You will have to purchase the sender and appropriate gauge and wire the darn sender to the console... Don't be surprised if it runs hot at full throttle, these motors have a history of running at 190-200 at full. But its good to know what is happening.<br />dingbat has a good suggestion of adding a pressure gauge, that way you will know when the stats and poppets open.
 

trumanlake

Petty Officer 2nd Class
Joined
Aug 8, 2003
Messages
131
Re: Water pump Flow on Merc. Black Max 150

atta boy kclost! Pressure gauge. The way to go!
 

rowland

Recruit
Joined
Sep 6, 2003
Messages
2
Re: Water pump Flow on Merc. Black Max 150

Thank you for all the good information. I do not know when the last time the water pump was serviced or changed. Sounds like when it doubt....DO IT..... :D <br /><br />You mention a pressure guage. Where and how would that install.<br /><br />Is the temp guage referred to a kit to intall on this motor or something you adapt?<br /><br />I have a digital thermometer from work I can use to test the water coming out the tell. When running at a good speed what temp should I see?<br /><br /> <br /><br />Thank you
 

KCLOST

Commander
Joined
Jun 22, 2002
Messages
2,095
Re: Water pump Flow on Merc. Black Max 150

Rowland, I imagine that you can get a temp sender and gauge for your engine at most mercury dealers/service establishments... The sender for my engine (which is basically the same as yours) will end up measuring the temp of the cylinder head, as it touches metal not actually measuring water temp. It will mount under the #2 cylinder on the port/left side of the engine.<br />But for me to know what the proper water temp. should be, I can't begin to guess. At full throttle don't even try to measure the water temp, you might kill yourself. <br />Trumanlake can really help you with the pressure gauge. I think it mounts on the top of the block, but personally I don't have one YET! This will let you know that the stats and poppet is working properly...
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Water pump Flow on Merc. Black Max 150

hello<br /> most of the v configured motors that merc has made use discharge water from the t-stats for tell-tale water. that is why it comes out about 140 degrees. I think merc should have done a better job of explaining how the telltale works in the owners manual because I get 20-30 calls about it every season.like all have said every 2 years its time for a diaphram in the pressure valve. if you dont belive it watch the water ingestion problems if it fails. a water pump and Tstats every other year as well. I have found the sierra t stats work better then the merc ones because they are self flushing and vented. the part number for them with seals is 18-3672. OMC makes a nice stainless one but the poppet seals so tight that water cannot get to it. but that is another discussion :) <br /> Good luck and may you never need a pump. I have found the price of the pump is constant whether I buy pistons with it or not :)
 

trumanlake

Petty Officer 2nd Class
Joined
Aug 8, 2003
Messages
131
Re: Water pump Flow on Merc. Black Max 150

rowland,<br />Think safety, don't lean over the back!!!!<br />There is a brass plug top rear on the block, remove it, that is where the pressure gauge will hook up. It's easy.<br />Kclost your missing some good fishing.
 

gss036

Commander
Joined
Jan 18, 2003
Messages
2,914
Re: Water pump Flow on Merc. Black Max 150

Rodbolt,<br />I get my engine serviced on a regular basis by a well trained merc mechanic and he has never said anything to me about T-stats and the diaphram in the pressure valve being changed every 2 years. Now you've got me wondering. I run a 1989 200 Merc and as far as I know mine have never been touched.<br />What does that take to change them. Are there 2 each?
 

Hasbeen

Petty Officer 2nd Class
Joined
Aug 29, 2003
Messages
167
Re: Water pump Flow on Merc. Black Max 150

I allways wondered what those guys were doing when I saw there wives driving the boat at 50 MPH and them hugging the outboard with there arm around the back of the outboard! I always just thought that they really liked there outboards!!<br /><br />Hasbeen
 
Top