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Johnson Seahorse 10 QD-21 Oil Leak

C

cdlmartys

New member
Hello All,

New member here and doing my best to search before posting. My Dad has a Johnson Seahorse 10 Model QD-10 he has had stored for about 20 years in his machine shed. He has decided to sell his boat, motor, trailer and we are getting things ready. Low and behold, the motor starts and runs well. However, after sitting on the boat for two days I noticed this:

There is a trail of oil coming from a hole on the underside of the Anti-Cavitation Plate (best way to describe the location from looking up a manual). Is this normal or a cause for concern?


We have no intentions of selling someone a lemon.

Thanks in advance.
 
That's most likely un-burned oil from your gas/oil mix. I'd be more concerned with the water pump. I wouldn't run the motor any more until it gets replaced. Being as old as it is it needs changing. If that quits pumping cooling water to the power head, you've just trashed the motor.
 
Find the large slotted drain screw on the skeg of the lower unit... NOT the philips screw, DO NOT remove the philips screw!

OKay, loosen the slotted screw just enough so that you know what the gearlube looks like. Compare what dripped out of the lower unit's slotted drain screw with what's coming out of that small hole you mention.

If they are the same... yeah, that's a lower unit leak.

If they are not the same, what you see coming out of that small hole at the cavitation plate is simply the unburnt fuel oil mixture draining down the long exhaust housing..... (normal).
 
Then that's what it is. Not to worry. But do check the gear oil, even though that's another topic. And don't trust the water pump.
 
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