It's not a sound you want to hear from an outboard engine.
The cause of the noise is shown in the photo. Can you find it?
If it took you less than ten seconds to spot the missing oil plug, good for you.
I don't know how the thing managed to vibrate out; we cinch them pretty tight when the oil is changed. But we hadn't checked the torque on the plugs in about 40 nautical miles of boating and 800 km of trailering. And it had loosened. So the plug is now somewhere in the sediment of a Northern Ontario lake, and while it sat overnight, a full charge of gear oil floated away and was replaced by lake water.
Lake water is not a good lubricant, nor is it a good hydraulic fluid. Like most outboards, this Johnson J30 depends on that 90-weight oil to keep things spinning, and without it, the gearset rattled like crazy in neutral and stopped dead when put in gear.
The response to a failure like this is:
- Get the engine out of the water.
- Drain the water from the gearcase and replace with fresh oil.
- Spin all the moving parts a few times to circulate the fresh oil and coax any remaining water out.
- Change the oil.
- After running the engine for a moment, drain a bit of oil and, if there's any remaining water or contamination, change the oil again.
- Hope that those 60 seconds of idling didn't do any permanent damage....