four stroke losing oil

[Jeremy]

Took my V17C with 140 hp Johnson four stroke out for a run on Saturday. Everything was going well until the 'no oil' alarm came on about 10 am. I was about 5 miles East of Manly at the time. I call up my mechanic who said it was probably burning a bit of oil and if I top it up it should be fine to head home. I came in towards Manly at about 1200 rpm until I was about 1.5 miles out and the no oil alarm came on again, so I switched it off and had to get towed the rest of the way by the Coast Guard :(. There was no strange noises or burning smell so hopefully there is no damage. Anyway I checked the dipstick which was almost dry, bought some oil, added about 200 mL to the engine and tried to head back out through Manly to Nudgee where I had launched. Alarm came back on so I went back to the ramp, got a cab to Nudgee and went and picked up my car and trailer.

I flushed it at home and there was definitely oil coming out with the water onto the driveway. I have since added the rest of the 1 litre bottle of oil and there is still no reading on the dipstick, so it mush have lost a lot of oil. Surely it can't be burning that much? I have only put about 30 hours on it since it was serviced. It ran smoothly and quietly with no odd noises. There was a bit of a smell of oil at times on Saturday, but no smoke when it was running.

Only thing I can think of is I hit a sandbank the week before. Done that before plenty of times with no issues. There is no oil leaking from the engine onto the concrete - no oil stains before or now which is 2 days later.

Spoke to the mechanic again today who said I should continue to top it up until it is full on the dipstick and take it for a run and see what happens. Not sure about that.

Where is the oil going?

[scottar]

Corroded sump a possibility. Not the first time I have heard of this in a 140 Zuk (and the other one detonated so don't run it without finding the problem) . I would pull the lower pans and have a good look around.

[Noelm]

I guess the very first thing is the obvious, take the top off and give it a run to see if there is any oil leaking under pressure, it must be a decent leak, but seeing as it was recently "serviced" places to look will be around the oil filter, and the drain plug, if it's burning that much oil, it would be smoking, so, it must be leaking, but probably only when running, some early 140s did have corrosion issues.

[gazza2006au]

Jer for what its worth i done a full engine rebuild on a Mercury 25hp 4 stroke took it out one evening and seen a little bit of oil leaking into the water i didn't think anything of it as it may have been some oil or fuel that leaked on the leg, we got about 4 to 5km's down river and the alarm sounded for low oil i thought that was strange i had just put new oil in it, we had to motor at idle back to the ramp, the next day i realised i left the oil cap off and it was jammed up near the flywheel

lost all of the oil

refilled it replaced the oil cap took it out quiet a few times more it ran beautiful lol

[Moonlighter]

Have heard some reports of oil filters that were tightened too far splitting.

Have also heard of after market (ie car) oil filters being used that do not seat properly and leak badly under pressure.

would be worth checking. Easy to do - refill with oil, take the cowl off, put the muffs on and start the engine. Will be obvious.