New Mercury 50 2 stroke 3 cyl water pressure

[Hyper]

I have a new mercury 50 2 stroke engine on my new boat and today I installed a new 30 psi water pressure gauge. I took out the pipe plug on the upper rear of the cylinder head by the top spark plug and installed the gauge. I have about 2 lbs of water pressure at idle and 8 at 4000 rpm's, I read the instructions and it said to install it between the spart plugs on a 50hp with a thormastat. I did not see no where to install the fitting between the spark plugs so I used the top right pipe plug. It pee's hard out of the pee hole but I am not getting much water pressure on the gauge and i eve bleed the gauge. Where do I need to put the fitting to the water line for the gauge? I know that something is wrong. My engine number is 0T729899, it is a 2003 50elpto. Please some help me....my email is j_watter@bellsouth.net or WatersRacing@bellsouth.net<br /><br />thanks again....

 

[Hyper]

Re: New Mercury 50 2 stroke 3 cyl water pressure

any help guys?

 

[SpinnerBait_Nut]

Re: New Mercury 50 2 stroke 3 cyl water pressure

Don't know hyper, but don't think you will see a big pressure with it puttin water out the pee hole also.<br /><br />No back pressure for gauge to read.<br />Just my .02 worth.<br />Might be wrong.

 

[Bob Kimber]

Re: New Mercury 50 2 stroke 3 cyl water pressure

Hi Hyper,<br /><br />Are you sure you a 30 psi gauge is the correct gauge for your engine? Most of the newer Mercs use a high volume but relatively low water pressure pump, for example the recommended gauge for a 3cyl 90hp engine is a 15lb pressure gauge. With this gauge and a new pump impeller you would expect to see about 4 to 5psi at idle and about 10 to 12psi at WOT (approx 5,500) on a 3cyl 90hp. <br /><br />My understanding is by fitting a high pressure gauge it will not indicate a true reading because of too much back pressure on system, the connection location on the head sounds to be similar to the other 3cyl models and has no influence on the amount of water at the telltale.<br /><br />Bob

 

[Hyper]

Re: New Mercury 50 2 stroke 3 cyl water pressure

yea the book siad 30 psi, so I ordered it from teleflex for a mercury 50. So I have a 30 psi gauge and only 8 psi of pressure at 4500 rpm's

 

[clanton]

Re: New Mercury 50 2 stroke 3 cyl water pressure

water pressure 0.5-1.5 lbs at idle, 5.0-7.0 lbs at W.O.T., for 40/50 HP.

 

[Hyper]

Re: New Mercury 50 2 stroke 3 cyl water pressure

thanks, now I need a 15 psi gauge instead of this 30...lol I thought something was wrong with the boat.

 

[papasage]

Re: New Mercury 50 2 stroke 3 cyl water pressure

why wouldnt a 30lb guage work . all guages are twise the top normal amount. papasage