Testing the water pump

[Sugo]

I have a 1990 Merc 135hp (On a 20ft Bayliner Trophy) I replaced the water pump but suspect it is not working correctly. I replaced the thermostats, popit valve and installed a water pressure gauge. At idle the water pressure gauge barely registers maybe 1 to 2 lbs it does go up when I increase the RPM over 1500. The water coming out the pee hole (after it's full warmed up) is only a very week stream as opposed to past outboards I have owned. The temp alarm goes off 2 min after the first take off of the day, I shut in down for 2 min then it is fine for the rest of the day. I did install a temp gauge but have not had it out to see if it is overheating or a faulty reading by the sender.
How can I confirm my water pump is working correctly? What is the correct operating temp range for this outboard?
Any tips would help.
Thanks

 

[carholme]

Re: Testing the water pump

Sugo;

What is the s/n and model number of your engine, if you have it?

Gerry

 

[Sugo]

Re: Testing the water pump

The serial # on my 135 merc Black Max is OC282933. I removed the lower unit yesterday to have another look at the water pump. When I replaced the pump last year, the kit did not include the base plate or the gasket under the base plate, so it looked ok so I never removed the base plate as to not disturb the gasket under it. (Big mistake) I removed the base plate for a better inspection to find that whoever had the boat before I purchased it last summer had installed the gasket under the base plate upside down. The bolt holes are symmetrical but passageways are not so the gasket installed incorrectly blocked 70% of the water intake. I felt a bit dumb that I had it apart to replace the water pump last year and did not notice this. I got lucky that it only cost me a few new gaskets rather than an overheated power head. Maybe someone might read this and avoid this situation. I hope this cures my overheating issues, maybe I will get the boat in the water in the next few weeks.

 

[carholme]

Re: Testing the water pump

Sugo;

Wello, I will just leave it at that and hope everything goes OK for you. Glad you found something obvious without too much cost.

Good Luck

Gerry