Water pressure

[hl]

I just replaced the water pump on a 1986 mercury 150 hp. the water tube came off when I dropped the foot.. After replacing the pump I pushed the water tube back up in the correct fitting . Cranked the motor on ears . The pressure climbed to 5 psi.,. Pushed the rpm to about 1500 rpm.and the psi went to up to 14 - 15 psi the back down to 5 and back up to 14 . The psi would continue up and down from 5 to 14 psi. Any ideas what might cause the fluctuation

 

[jimmbo]

Don't trust any reading when running on muffs. See what it does when in the water

 

[hl]

I have always tested on ears after doing any work on the motor. The psi would always read a normal range depending on rpm. I just don't understand why the psi fluctuate now.

 

[jimmbo]

What condition were the Grommets for both ends of the water tube?

 

[hl]

I put a light up the exhaust ..The water tube grommet looked ok and the water tube went in and seem to be tight.

 

[hl]

could the poppet valve cause this?

 

[Faztbullet]

Yes ….that is poppet cycling..

 

[hl]

Thanks, I will replace this the first chance I get and post the result

 

[hl]

It has been a while since I went through the poppet valve. I took it apart and everything seemed to be ok. I took it to a marine specialist and he could not see anything wrong with the diagram. I put everything back together and started the motor. Water began to come out of the weep hole of the poppet valve cover..Took everything back off and started over. Water still coming out of the weep hole. I asked several people why this is happening. No one knows. Does anybody have an idea

 

[racerone]

You say ----" weep hole "-----I say that is a vent so that the diaphragm can move / respond to water pressure.------No water should come out of that hole.-----It simply means that there is a leak that you have missed / over looked here.

 

[hl]

Thanks, The first chance I get I plan to start over. From the water pump, water tube and poppet valve.. I will post the results.