Mecury BlackMax 175Hp, Constant Beep and Overheating

[Robertse]

Was the old impeller in 1 piece? did you check the sensor itself? Do you know if that is a 2.5 litre? If not somebody here might know.

Hi Scott, yes the old impeller was in 1 piece and in good condition, a but hard, but no pices missing from it, but I replaced it away. It is a V6 175Hps 2.5 Litre. The water comming from the tell tail is reasonably hot, and the heads covers heat up. I will check the sensor, can you please point me to that sensor? i will also do a compresssion test.Thanks in advance.

 

[Robertse]

Hi Scott, yes the old impeller was in 1 piece and in good condition, a but hard, but no pices missing from it, but I replaced it away. It is a V6 175Hps 2.5 Litre. The water comming from the tell tail is reasonably hot, and the heads covers heat up. I will check the sensor, can you please point me to that sensor? i will also do a compresssion test.Thanks in advance.

So No lower unit AND a garden hose feeding the cool water tube to the engine works fine ?
Could be the exhaust system casting is blowing hot gases all over the pumping system down there ?
What else is left to heat up the water so much ? Geezer engine problems.

Hi CY, See the below answers.. So No lower unit AND a garden hose feeding the cool water tube to the engine works fine ? YES
Could be the exhaust system casting is blowing hot gases all over the pumping system down there ? I think it is smoking a bit over a normal 2 stroke.
What else is left to heat up the water so much ? Geezer engine problems.

 

[Dukedog]

did you do tha complete water pump kit or jus tha impeller?.. if it works with a direct hose and not with tha gear case pump then it sounds like a supply problem???... how hot is "hot"?.. does it alarm?.. need a pressure gauge.. makes life easier.

 

[flyingscott]

So if it is the newer 2.5 litre your tell tales will be warm/hot as they are connected to the Thermostats.

 

[Robertse]

did you do tha complete water pump kit or jus tha impeller?.. if it works with a direct hose and not with tha gear case pump then it sounds like a supply problem???... how hot is "hot"?.. does it alarm?.. need a pressure gauge.. makes life easier.

Hi Duke, Yes I replace the whol impeller kit, inlcuidng housing. It pumps water fine and strong, the water is not boiling, but hot enough for you not to keep you hand for too long under the tell tail, is that normal? Because on other 4 stroke engines I notice the water is much cooler. The Alarm trippers as soon as I turn the key with a cold engine, so may be it is the sensor?

 

[flyingscott]

If that is a 2.5 , the tell tales do not fully flow until the thermostat opens. I believe those have 140 degree thermostat so yes toasty water comes out. Not all Motors plumb the tell tales that way. That is kind of a Unique feature to some Mercury 2 strks.

 

[Robertse]

If that is a 2.5 , the tell tales do not fully flow until the thermostat opens. I believe those have 140 degree thermostat so yes toasty water comes out. Not all Motors plumb the tell tales that way. That is kind of a Unique feature to some Mercury 2 strks.

You are correct, the Tell Tales takes about 1-2 minutes before the start to pee. May be I just have a bad sensor, which I will look into next...

 

[flyingscott]

That tells you your thermostats are working. Get an infared gun to double check the actual temps. The switch should be in the head itself If I remeber right. Dukedog or Fatzbullet will be much more help on that.

 

[Dukedog]

99.9% of all production 2.0, 2.4 and 2.5's have 143* stats.. they all work tha same.. you say you are goin' by "feel".. thats no wanno. 140+ degrees is pretty warm.. you can get yourself a cheap heat temp gun to get real time reading on tha motor.... are you getting a constant BEEEEEEEEEEEEEEEEEEEEEP or and intermittent BEEP?? are you getting tha three self test beeps when tha key is turned on?... thats if its still got tha oiler intact.. does tha alarm start instantly when tha key is turned on or does tha motor need ta run a while before it alarms?

 

[Dukedog]

One thing I noticed, while the leg was off, during the impeller replacement, I connected garden hose at the bottom of the water tube which runs up to the engine, it was pushing water strongly out of the peep (tale tail) hole and at this one stage there was NO warning beeping. But when I put the leg back on, the beeping occurs. The next thing I will do is a compression test.

I am lost because I tried all listed above.

Warm Regards,

this pretty much tells ya its a pressure issue between tha pump and tha block.. when you had tha pump apart did you look into tha void under tha pump where tha intakes are?.. are you positive that tha plastic "guide tube" is doin' its job with tha copper tube alignment?.. was there a rubber grommet in tha top of tha pump housing?.. copper tube "seats" into this grommet..

JAN... a pressure gauge would eliminate a lotta this guessin'......

 

[Robertse]

99.9% of all production 2.0, 2.4 and 2.5's have 143* stats.. they all work tha same.. you say you are goin' by "feel".. thats no wanno. 140+ degrees is pretty warm.. you can get yourself a cheap heat temp gun to get real time reading on tha motor.... are you getting a constant BEEEEEEEEEEEEEEEEEEEEEP or and intermittent BEEP?? are you getting tha three self test beeps when tha key is turned on?... thats if its still got tha oiler intact.. does tha alarm start instantly when tha key is turned on or does tha motor need ta run a while before it alarms?

Hi Duke, before I was getting an intermittent BEEP within a few second of starting the engine. But Now I am getting a constant BEEEEEEEEEEEEEEEEEEEEEP as soon as I turn the key (instantly) and the motor starts. I disconnected the oil senor, and the constant BEEEEEEEEEEEEEEEEEEEEEP was still there.

 

[Dukedog]

an "instant" beeeeeeeep is usually a bad oiler module... disconnect tha purple feeding tha oiler module or disconnect tha tan coming from tha oiler module at tha small term block on tha starboard side.... or both.