fuel pump check valves

[tony murray]

hi does anyone know?
iv just replaced my fuel pump check vales on my1983 merc 70 3cyl.
but im not sure which way round they go?
is there an easy way to tell the manual seems pretty vague.
thanks

 

[mrallen007]

Re: fuel pump check valves

Not sure if this will be any more clear than your manual, but here are some basic schematics of your fuel system. Does this help at all?

http://www.crowleymarine.com/mercury-outboard/parts/675_9.cfm

 

[Chris1956]

Re: fuel pump check valves

Easy, they are one-way valves. The fuel comes into the pump from the fuel tank on one side. The one way valve needs to allow this. so base down for this one. The other valve allows fuel to exit the pump, so base up for this one. Test by blowing thru assembled pump. if air travels from fuel tank side to motor side, valves are correct.