Water flow diagram for 1975 9.9 Johnny

[rolmops]

Is the 1975 water flow diagram any different from the water flow diagram in a 1993?<br />I do have the OMC manual with a diagram for a '93 9.9 but I don't have the 1975 manual and before buying it,just for a flow diagram, I would just like to pick our communal brain a bit.Thanks for any comments and help.

 

[OBJ]

Re: Water flow diagram for 1975 9.9 Johnny

Just right off the cuff....'bout the only thing that changed is where the t-stat is. 75's at the bottom of the head....93's at the top. T-stat is different also. Best I can do without referring to the manuals flow diagrams.

 

[OBJ]

Re: Water flow diagram for 1975 9.9 Johnny

rolmops....took a look at the flows. The early 9.9/15's had a head cover that housed the t-stat and directed out flow from the t-stat to the exhaust.<br /><br />The later 9.9/15's with the t-stat at the top of the head did not have the cover. The flow from the t-stat was directed back through the head and out to the exhaust.

 

[rolmops]

Re: Water flow diagram for 1975 9.9 Johnny

Originally posted by OBJ:<br /> rolmops....took a look at the flows. The early 9.9/15's had a head cover that housed the t-stat and directed out flow from the t-stat to the exhaust.

That is exactly what I needed to know.Thank you very much.

 

[OBJ]

Re: Water flow diagram for 1975 9.9 Johnny

Anytime rolmops.....

 

[rolmops]

Re: Water flow diagram for 1975 9.9 Johnny

Ok I figured out my problem.<br />The aftermarket gasket between the cylinder head cover and the cylinder head was a touch to big and partially covered the overflow outlet near the thermostat.This caused back pressure and a leaking seal.It is always a small victory to figure these things out and with the help of the good people on this board,the victories become more frequent.<br />These old engines are journeys of discovery and every time I figure out another little piece of this down to earth technology, it gives me a deep feeling of satisfaction and joy.I can honestly say that this board has made my life richer.