Leaking Yellow fluid in a 1973 Johnson 25hp outboard, and no impellar water?

Question

There seems to be yellow liquid leaking from what seems to be near the prop on the motor. I have a feeling it's the gear oil and i have a leaky gasket but i just want to be sure. Also there doesn't seem to be any water coming out from the impellar. Does it come out near the prop because the prop is a pin drive not a through prop exhauhst. I just bought the motor and i only ran it at idle. I want to get all the problems out of the way so i dont blow it up on the water.

Answer 1

Oops you may have just bought a problem motor.  Hope it was cheap.

Yellow fluid is grease for sure.    And it's the "lower unit" very expensive and difficult to work on.  More so than even the engine/motor itself.  No water circulating probably means the impeller has all the fins worn or broken off.   Age,  running in gravel or sandy water kills these easy. It's 35 years old and the impellers are usually rubber.    

The repair may cost more than you paid for it.      Look around for a similar outboard with a shot motor and good lower unit.   Lot's easier to swap the lower unit than repair one.    

Lower units look as complicated inside as an automotive auto trans with small gears and washers.   Special tools needed usually to break them down.  (I know I took one apart once and threw my hands in the air)

Oh and remove the unit from the old one first to learn how to do it before tearing into yours.

Goodluck

RoyG

KC

Answer 2

the golden fluid is gearcase oil.  you should change the oil & replace the gaskets, & drain it again after the next outing to see if that resolves the problem.  if it doesn't, you'll need to re-seal the gearcase.

the exhaust outlet for that motor is under powerhead

Answer 3

Many of the older motors would "weep" oil from the lower. To see if it has a real problem- loose the large slotted drain s***w. See what comes out. If you gets lots of water I would get it to the repair shop. If you can put a chain on a bicycle- you can reseal this lower unit yourself. Get a nice repair book and follow the directions. This engine may have a thermostat which dumps at the holes below the power head. Most would come out the exhaust relief below the cavitation plate. The real answer is to put you hand on the exhaust cover just after you start up the motor. If it get so hot you can't hold it there, then the impeller is shot. Your new book will give you a list of services and when they should be done. Do them all.