Home › Forum › Ask A Member › 40s Johnson and Evinrude › Re: 40s Johnson and Evinrude
February 15, 2016 at 6:57 pm
#32011
It’s the idle relief valve. A little stainless cup inside slides up or down to open or close the valve. There’s no water pump to deal with on the PO’s as they have the pressure/vacuum system which relies on the prop and boat movement to force water thru the cooling system.
Nice motor Jerry! Hopefully mine will be looking that good some day!