bcfountain

how much water pressure is too much?i had a lower unit on the drive replaced and the new one has a low water pick-up on it.the old one did not.my pressure was 20 at wot w/old unit,now it is 35 plus at wot.is this too much pressure?

Carder

I don't think so.. I believe mine run up to about 40 psi when running hard.... obviously it's when it drops off the trouble starts. Carder

monstaaa

depends on your power, if it's fresh water closed cooling or not. if it's a stock mercury power , say 496, then its just a lil high. anything more than 35 may set an alarm, as i have seen stock power with 35 or 40 p.s.i set off the guardian alarm for pressure being to high.

if you have after market power than the pressure should be around 20. 20 at speed is perfect. you get good volume as to not create hot spots and adequate pressure to move the volume thru the cooling system so you dont end up with saturation issues.
this scenario has come up with boats switching to imco units as the water inlet on these units tends to dramaticly increase pressure's.

the ending result is poped intake manifold gaskets or possibly head gaskets. and if your unfortunate the water will enter the oiling system with out your knowledge at speed, and here comes trouble.

be carefull;.