Flushing 84 Johnson 25hp outboard (J25TELCRD)

jonduck

Cadet
Joined
Jun 2, 2010
Messages
6
I recently acquired a J25TELCRD outboard that I plan to run mostly in salt. Unlike a couple of other outboards I've had it does not have obvious cooling vents to flush with mouse ears hooked up to a hose.

In poking around on The Internet it seems as though it gets its cooling water input via the exhaust vent under the rear of the cavitation plate.

J25.Prop.Exhaust.jpg



I found this picture in a SELOC manual that shows a similar outboard with a flashing attachment. (It seems this was probably made by Tempo who is long out of business.)

J25.Flush.Attachment.jpg



I found other references to reverse gear cooling that enters though some small vents on the left side of the lower unit.

J25.Reverse.Intake.jpg


Would it work to put some square mouse ears over this to provide cooling water for flushing?


Where I plan to use the boat I do not have running water except at the driveway entrance so using a barrel would be a PITA. If I do need to resort to using a barrel what is the minimum depth of water I'd need to use? (On a scale of 1-10 based on the following picture.)

J25.Flush.Depth.jpg
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
With a bit of handiwork, you can make yourself a plate with a water hose connection to replace the reverse water intake plate for flushing. Warning--put the original plate back on before next boat launching.
 

jonduck

Cadet
Joined
Jun 2, 2010
Messages
6
Since both intakes are below what I have marked as 2.5 I don't see why I couldn't flush it in water at a depth of 2.5 to 5.
 

jbuote

Lieutenant Junior Grade
Joined
Aug 17, 2016
Messages
1,001
I don't think the water pumps are self priming, so you need the water level to be ABOVE the water pump (impeller).. This way, water works into those intakes, and up into the pump.. Then it will work.
​If below the water pump, it won't "Suck" in the water from below, and you'll be running the impellor basically dry as if it wasn't in water at all..

I think that's correct anyway...
 

Vic.S

Rear Admiral
Joined
May 4, 2004
Messages
4,720
Since both intakes are below what I have marked as 2.5 I don't see why I couldn't flush it in water at a depth of 2.5 to 5.
As jbuote says you need the water level to be above the water pump
 

heypawpaw

Petty Officer 2nd Class
Joined
Dec 12, 2016
Messages
111
As F_R said make a flush adapter to put in place of the reverse intake plate.(Check out Leroy's Ramblings he shows how to make one with old mercury adapter but reducer and pipe fittings would probably be cheaper. to connect hose to small plate. you use a barrel water pump is between 5 and 7.5 so water at 10 keeps it submerged. Wile engine is mounted on the boat and tilted down water pump is submerged below the water and works as it should. If you tilt engine enough to get pump above water it will not pump even if intake holes are submerged.
 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Since both intakes are below what I have marked as 2.5 I don't see why I couldn't flush it in water at a depth of 2.5 to 5.

The pump isn't self-priming. Needs to be at the 7.5 mark at minimum, with 10 preferred.
 

jonduck

Cadet
Joined
Jun 2, 2010
Messages
6
With a bit of handiwork, you can make yourself a plate with a water hose connection to replace the reverse water intake plate for flushing. Warning--put the original plate back on before next boat launching.
Well, four years later, time to bring this thread back from the dead.

Was poking around on Ebay today and stumbled across this which seems to be exactly what you described:
 
Top