1977 70 hp Johnson - what are these springs

[John90290]

I changed the thermostat and there are theses two springs with a plastic pluger type thing on the ends. The kit did not come with replacements, not sure if I need to replace them.

The springs fit into the housing and the other end of the plunger goes into two holes that are outlined in the picture of the gasket.

Thanks,

John

 

[bankerjohn]

Re: 1977 70 hp Johnson - what are these springs

Those are pressure relief (poppet) valves, grommets and springs:

They're used to bypass the thermostat when the engine is running at higher RPM's ... when the water pump impeller is pushing out a higher volume of water.

As far as replacing them when you replace the thermostat, for the relatively little they cost, I'd probably replace them if I was replacing the thermostat on a 32-year old engine!

 

[John90290]

Re: 1977 70 hp Johnson - radical flushing idea.

Re: 1977 70 hp Johnson - radical flushing idea.

Thanks!

This is my thought.... my boat lives in salt water and after each use I strap on the rabbit ears and run water through the outboards. The problem is I'm not sure how much salt water might be sneaking into the fresh water when the rabbit ears are under water ( I cannot run the motors when they are tilted up)

I was thinking of running fresh water (using a fitting I fabricate) through the water outlet ports. If the motors are not running and are without thermostats (I live in California) the water should theoretically shoot out water pressure tell-tale that can be installed per the instructions on this forum... is this crazy?

Even if it is, would it work?

 

[tashasdaddy]

Re: 1977 70 hp Johnson - radical flushing idea.

Re: 1977 70 hp Johnson - radical flushing idea.

the motor was built to have tstats, to keep the engine at proper operating temperature. you are not getting enough salt water mix to hurt, as the hose pressure is higher and squirting out around the muffs. just run the motor long enough to open the tstats. just because you have water out the tell tale, does not mean the tstats are opening.