b79 MERC 20 HP LOWER UNIT VENT SCREW

[Pat Corey]

" Gents, I can't find the

" Gents, I can't find the lower unit vent screw on my '79 Merc 20 horse. I got the old stuff out the lower drain hole after removing the plug screw and didn't get much in without venting the top of the cavity. The upper plug screw I did take out was a hard fiber deal that I later found said 'flush' next to it. Can somebody point me to the vent plug? "

 

[sparky]

The flush screw has to do wit

The flush screw has to do with the cooling system . The vent screw is a small screw ( 3/16" diameter) look for it it is there.

 

[Pat Corey]

" Sparky,.....Thanx so much fo

" Sparky,.....Thanx so much for the info. Being an old OMC guy and relatively umfamiliar with the "black" engines I didn't recognize the screw as such. It's small size fooled me and the last time I took a small screw out of an older Evinrude (in ignorance), it turned out that it held the shift rocker in place. That's how I learned to separate the lower half of old OMC lower untis! Can the "flush" screw/plug hole be used to adapt a hose so I wouldn't need the mickey mouse ears to run it in the yard?....Thanx again, .....Pat "

 

[sparky]

Not sure if you can run the m

Not sure if you can run the motor. I think it was meant to flush motor after salt water use.