low water preasure
 

I just recently purchased a 91 32 foot fountain with twin 502 mags. I have lower water preasure reading on the starboard side and I changed the impeller with no increase of preasure on the guage.Does anyone know where I can find the sending unit and what to look for?

Thanks
Running A Fever

Re: low water preasure
 

hey did you get that from columbia sc

Re: low water preasure
 

Should be a mechanical gauge, no sender used. It will be hooked to the block at 1 of the lower block drains. You 'may' have a partially blocked hose for the guage since the connection point is prone to being the spot where rust and sand sediments settle plugging the hose.
Did you back flush the water inlet hoses thru the coolers while the impellor was apart?

Re: low water preasure
 

Swap the hose under the dash and compare,
As US1 Fountain said the hose connection on the block most likley has trash in it. take the hose off under the dash and blow air through it.

Re: low water preasure
 

No I got it in Lake George N.Y. From a guy named Rick,He has been on this forum for years and told me about it.

Re: low water preasure
 

ok there was one in sc that had runnin a fever on it thanks

Re: low water preasure
 

A customer of mine had the same problem on his 32. The problem was a cracked Flushing Valve. This is a plastic piece that also let water into the bilge. (even more water than normal 32's) VERY inexpensive fix. The part is a Flush Pro Marine Flushing Valve. I hope that is your problem. Let me know.

Frankie
Pier 57

Re: low water preasure
 

I didn't flush the cooler,but I did take the line off the guage and it is blocked at the engine. I just need to get under and remove the hose on the block, I think. I'll let you know how it goes.

Re: low water preasure
 

Hey Nordic 95. Its me! Rick :D.Two things,when you
change the impeller I always buy the kit with a new
housing. If that housing is scored at all,it will really
affect the pressure. Also when installing,always pack
the impeller with vasoline.The hose is attached to the
left side of the engine below the exhaust manifold
in the center port. It will definetly be partially plugged.
Take it off ( a pain to get at) and stick a drill bit in
the fitting to clean it out.
How do you like her. Hope its runnin great and your
enjoying it!! P.S how do you like the picture of your
boat in my avitar. Looks great doesnt it!! :D

Re: low water preasure
 

Hey Rick

I did replace the housing and all. It still reads 0 psi at idle and 7psi at 3500. I figured is was clogged because at idle the engines now run the same temp.I really love this boat,It is such an eye catcher,even on the way home that day people were giving thumbs up on the thruway.I knew I would hear from you on here someday,as soon as I got home I joined.Thanks for the link.Talk to you soon.

Re: low water preasure
 

Finally got the hose cleaned out at the block.It was really clogged with silt.This was on my starboard engine and my port gauge now reads 7 psi at idle and pins 35 psi at 3000 rpm, higher then it did before.Is this too high for raw water pressure ?And also my hoses must be crossed some where because my starboard guage still reads the same as before 0 psi at idle and 7 psi at 3000 rpm.Now I need to clean out the port engine and check the routing of the hoses.What should the max pressure be and why would it be so high?

Re: low water preasure
 

tttt

Re: low water preasure
 

You have basically no pressure at idle. That's normal. The 7 is low. double check the WP hose, sea water pump for correct hose connections and for broken impellor vanes.

"ideally' max pressure should be around 20*. I have the same high pressure as all stock BBC do aand will blow water past the seals in the wp at wot runs and into the bildge.

Re: low water preasure
 

What controls the pressure?any way to adjust it?Still wondering why the other is much lower.I will check it out if the rain ever stops.

Re: low water preasure
 

The pressure is derieved from the T-stat housing and the exhaust. I take it yours has the brass tee on the stat housing. Those were never a problem like the newer design. Merc makes a relief valve ( for a problem they say doesn't exist), but it doubled in price last fall. Something around $250ish.

Re: low water preasure
 

:D :D :D I guess they realize how many people have the problem that doesn't exist. More profit!
Dan

Re: low water preasure
 

I'm going to flush the system out and clean all hoses and change thermostats.Maybe its a stat hanging up or something.What would it hurt yo run at 35 psi?Probably head gasket right.I was also told the 502 should have heads redone about every 350 hours.Whats your thought?Motors have 535 hours now and run good.Just wondering if I should do them over winter or not.