1993 Mariner 150 - engine stops peeing when reved up

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I just purchased a boat with a 1993 Mariner 150. Just changed the impeller but water still quits when I rev the engine. Steam is visible when water is coming out of pee hole. Any suggestions?
 

Chris1956

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Re: 1993 Mariner 150 - engine stops peeing when reved up

Check the thermostats and the poppit valve. Rebuild poppit, replace thermostats if any doub't about if they are working.
 

Mi duckdown

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Re: 1993 Mariner 150 - engine stops peeing when reved up

Did you get copper water tube into the head installed properly?
 

MH Hawker

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Re: 1993 Mariner 150 - engine stops peeing when reved up

Is it on muffs or in a lake
 

CharlieB

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Re: 1993 Mariner 150 - engine stops peeing when reved up

P stream comes off after the stats, if cooling water pressure increases and the popit valve opens the motor can cool and the stats close

How warm is the motor? Can you hold your hands on the cyl heads for 2 - 3 seconds without screaming little a little girl?

Temp melt sticks are a great tool, a laser temp gauge as VERY neat.

140 - 145 is fine, any more you need to look into cooling system more.
 

Texasmark

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Re: 1993 Mariner 150 - engine stops peeing when reved up

P a laser temp gauge as VERY neat.

Harbor Freight has the non-contact laser digital temp sensor for about $25 on sale now. I use mine all the time. Even use it to check my catfish frying grease to ensure it's over 350 before I toss the fillets in.

Stat starts opening at 143F. OT alarm goes off at 195. Popoff opens at around 2500 rpms and bypasses the stat for improved cooling at the higher speeds where increased cooling volume is required and temperature control isn't.

Mark
 
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Re: 1993 Mariner 150 - engine stops peeing when reved up

Running on muffs after replacing impeller and tstats. Seems better but not positive, need to get on water. Have poppet kit on the way to be safe.
Anyone know what the water pressure should be for this motor?
 

Texasmark

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Re: 1993 Mariner 150 - engine stops peeing when reved up

Running on muffs after replacing impeller and tstats. Seems better but not positive, need to get on water. Have poppet kit on the way to be safe.
Anyone know what the water pressure should be for this motor?

Around 2.5 at idle and 6 psi at WOT will get you close if not dead on.

Mark
 

carholme

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Re: 1993 Mariner 150 - engine stops peeing when reved up

From the manual:

12 PSI Minimum @ 5500 RPM

Gerry
 

MH Hawker

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Re: 1993 Mariner 150 - engine stops peeing when reved up

On muffs it may simply not be getting enough flow to keep at higher RPM`s and you shouldn't run it at much over a idle I would back it down into a lake and see.
 
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Re: 1993 Mariner 150 - engine stops peeing when reved up

Getting about 7psi at idle and around 10psi @ 3000. Nice steady stream, not intermittent any longer.
 

Texasmark

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Re: 1993 Mariner 150 - engine stops peeing when reved up

From the manual:

12 PSI Minimum @ 5500 RPM

Gerry

Guess my 90 numbers don't work for the v engine. Guess they use more pressure as the volume is much larger and it helps it to get circulated.

So, I apologize for the dis information.

Mark
 

CharlieB

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Re: 1993 Mariner 150 - engine stops peeing when reved up

The addition of a water pressure gauge to your boat is about THE best way to keep an eye on the cooling system, immediately know the pressure at all times.

Pressure will rise with RPM, somewhere @2500 you should notice the pressure take a step down, this is where the popit valve has opened and full flow begins, from here on the stat's don't make much difference. Depending on water temp the stats can close and the motor remains within tolerance yet on the low temp side, even at max load WOT.
 

Texasmark

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Re: 1993 Mariner 150 - engine stops peeing when reved up

Guess my 90 numbers don't work for the v engine. Guess they use more pressure as the volume is much larger and it helps it to get circulated.

So, I apologize for the dis information.

Mark

Today I was in my shop manual and realized the root cause of my disinformation. I was quoting fuel pressures not water pressures. My 90 manual states 10-12 psi @ 5250 rpm.

I knew I had seen those numbers I posted in the manual, just got in the wrong pew as the saying goes.

Again my apologies.

Mark
 
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Re: 1993 Mariner 150 - engine stops peeing when reved up

Gerry, where can I find a manual?
Does this motor have a rev limiter? Previous owner stated not to go over 5200rpm so I have stayed clear.
 

carholme

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Re: 1993 Mariner 150 - engine stops peeing when reved up

You got it figured out, good for you. The manual is on it's way to you.

Gerry
 

CharlieB

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Re: 1993 Mariner 150 - engine stops peeing when reved up

Gerry, where can I find a manual?
Does this motor have a rev limiter? Previous owner stated not to go over 5200rpm so I have stayed clear.

Most outboards the prop is the rev llimiter.

Prop size and pitch is changed to allow the motor to run within the specified RPM range at WOT.

Most prefer prop pitch allow the motor to run near the upper limit as an under-loaded motor will last much longer than an over-loaded motor. Even that small difference in load between operating at the lower end of rating to the upper end of rating can make a world of difference in how your boat responds and how long your motor will last.
 
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