1973 Johnson 20HP?flushing procedure?

[jimmwaller]

Hi all,

I recently used my 1973 20hp Johnson outboard in salt water for the first time, and I'm unsure about how to flush it. I was reading up in flushing procedures, and the most thorough site I found mentioned that most engines built after 1974 can just use muffs. It said that the reason for this is that motors up to '73 don't have side intakes, they intake water through screened ports in the back.

I looked my engine over today and embarrassingly couldn't figure out where my intake ports are. Anyone know how to flush these '73 20HP johnsons? Photos are coming very soon, I took them on my phone so they're currently on their way to my email

thanks!

 

[jakedaawg]

Fill up a large trash can. Put wngine in it so the water comes about 4-6 inches above the seam where the lower meets the mid section. Put a.hose in the can to keep it full. Run it for a bit. You'll be fine.

They used to make a flushing attachment for those but i dont think you can buy them anymore. Start hitting garage sales

 

[jimmwaller]

ok, thanks! Yeah my phone is taking forever to email all these photos 18 inches to my computer, but I'll take your advice. Appreciate it!

 

[oldboat1]

^^^agree with jakedaawg. No need to rev it (shouldn't do that), and check engine temp. Shut it down if the top of the head is too hot to touch. Spray it all down well.

 

[jimmbo]

The water inlets on your engine are, on the front of the exhaust snout, and one on the port side right above the anti-ventilation plate