Newer style thermostat housing

[995jim]

I have a 90 454 Merc with newer thermostat housing, it has a pin with a spring loaded ball on 2 ports of the housing. Can someone explain what those spring loaded balls actually do? Thanks.

 

[Bt Doctur]

With any marine engine when running, water must exit the motor to cool the rubber components.The check balls shut when the thermostat opens to allow the water to go thru the manifolds and then the riser and out the exaust. with the therm closed water pressure pushes past the check balls and into the risers

 

[Bondo]

Ayuh,.... The spring tension should only just barely hold the balls in the holes,....
Very, Very little tension,....

Did ya stack the t-stat housin' back together in the right order, with the t-stat where it belongs,..??
With the brass rivet gasket,..?

It's quite impolite to hy-jack another poster's thread too,...
So,... Always start a thread of yer own,....
'n you can always link another thread to yer question, if info in that thread is critical to yer question,....

Thank you,...