Re: poppet valve?????
If the water pressure on the engine runs about 1 to 3 psi at idle you should NOT be concerned. The poppet valve controls the water pressure when the engine speeds up, to prevent OVER PRESSURE. If the water pressure were allowed to continuously exceed spec pressure, it could cause the cooling water to be forced into the cylinders (definetly NOT good)! If the pressure gage shows no pressure at idle, it could definitely be a cause. The poppet valve is located at the base of the power head (follow the water lines... one line supplies the pressure gage, the other will be connected to the poppet valve housing at the bottom of the power head. I just rebuilt my poppet valve (diaphragm and gaskets for $12). I have a 97' 150 Hp Merc V6.
<br />Ive been reading some posts that talk about this valve and Im just curious if I need to change mine or what do I need to do to fix it. I have a 76 1150 115hp ob.<br /> <br />thanks <br />Ben