leaking oil

[Mr Nofish]

Any body had this problem I've got a Merc 50hp 2stroke and it's leaking oil from the level sensor in the 2stroke oil container. Have pulled it out and it seems pretty basic just a self taping screw and a washer it holds down a plastic sleeve which puts presure on the sensor and seals it, but i can't see anything wrong with it. Help Please

[PADDLES]

i know that the oil tank cap on my my merc split at the top from it being done up too tight. expensive cap too because the level sender is built in to it. nothing like that has happenned to you has it?

[Roughasguts]

Is the self tapping screw gone through the tank and holed it.
Don't think it's suposed to do that.

[Marlin_Mike]

I have a 2003 Mariner 75hp 2 stroke.

When i tilt it right up high on the built in chock when towing it, it leaks a bit of oil onto the trnsom. I was told by several dealers and people this is a ommon fault with the Mercs.

I bought a yolk to support it back to the trailer. This elaves it alot less tilted, and hence the oil leak is no more.

Is this how yours leaks Nofish?

[Crooked]

Mr No fish,
Tie a rope around the leg just below the block, make sure it is good and tight, then tie the other end of the rope to your anchor post......then when you want to stop somewhere for a while throw the whole thing over the side! I hear this works very well with Mercury's keeps you right on top of your fishing spot. Don't worry that you can't use the motor to get home because it probably wouldn't start anyway!!!

Only kidding, obviously I'm not a Mercury fan. You say that there is a washer that helps it seal, is the washer stiff and brittle? If so it may not be sealing properly and you need to get a nice new pliable one.

cheers, Evan

[Mr Nofish]

Thanks for the info guys, Paddles i have no problem with the oil cap itself the oil is leaking from the bottom of the tank my cap has no level sensor in it. Roughasguts i had a look when i pulled it out did't seem to go right through it looks like its leaking from where the sensor go's into the tank. Mike its leaking from the bottom of the tank weather its tilted or not, the sensor dose not seem to be sealing to the oil tank. Thanks again for the comments

[Mr Nofish]

yep starting to feel a bit that way myself Evan but like you said would have no way of geting home, this is the first trouble i have had with the motor. The washer is stainless steel and it only puts presure on the plastic sleeve witch in turn pushes against the sensor sealing it to the oil tank.

[Mr Nofish]

yep starting to feel a bit that way myself Evan but like you said would have no way of geting home, this is the first trouble i have had with the motor. The washer is stainless steel and it only puts presure on the plastic sleeve witch in turn pushes against the sensor sealing it to the oil tank.

[bdm56]

Mr Nofish

I have a 50hp Merc with same tank as yours by the description (2002 model).

The sensor does not enter the tank at all, rather is retained in the tube moulded for this purpose and apparently there is a magnet setup on the inside of the sensor area in the tank. I know as the magnet fell off (common) and the low oil alert was sounding all the time the ignition was on.

2 choices in my case, pay the $180 for a new tank or disconnect the sensor (big risk - not recommended).

I even paid the $20 for the sensor but this was not the problem.

So in brief your tank has developed a hole/split somehow and only option will be either a new tank or try someone like Southside Outboard Wreckers or Burleigh Outboard Wreckers for a second hand unit and risk the magnet problem.

Good luck

[Roughasguts]

You can weld a plastic tank. Just need to find the same type of plastic and a fairly cool soldering iron, melt it in and your done.

[Mr Nofish]

Thanks for the heads up 56 will have a look tomorrow and than get on the phone

[bdm56]

Yep, but I think this one is split/leaking inside a tube which is bout 3/4 of an inch in diameter and bout 3-4 inches long.

Worth checking out though if the leak can be located, hope it's accessible.

Other problem is I think it's polypropylene and I don't it's weldable when I think about it, maybe wrong though.

[Owen]

Mr Nofish
I have a 50hp Merc with same tank as yours by the description (2002 model).


I have the same donk with the same problems. Oil alarm magnet gone, leaks oil when full & tilted.

At least they're consistant :thumbsdown:

cheers,
Owen

[Mr Nofish]

Hey 56 took of the oil container found the tube the sensor go's into has broken off all together and was rattling around in the bottom. Looks like i'm up for a new oil tank. Thanks for the help Mark

[bootyinblue]

No Fish,

I have a 40hp Mercury 2006 model and dumped oil all over my garage floor (not happy). Spoke to the guys and under warranty they just ordered a new oil bottle and sender unit. They commented that the factory were using wrong size self tappers and some were piercing the bottle when they bottomed out in the hole and others were not holding the metal probe up tight and creating a seal. The probe does go into the bottle and not into a sleeve, so oil can leak out around the base if not sealed.

No idea how much a new set up cost as was done under warranty, but maybe if probe and all works still, then some gasket sealer might stem the flow.

[bdm56]

Just finished a full strip-down (not internals of power head or gearbox) and want to warn anyone with these motors.

Watch out for corrosion, bit shocked to find a lot of components I would have thought to be 316 (marine grade) stainless are actually hardened steel with a bit of cad plating. Power head to leg bolts, trim tube and nuts, main mount bolts and nuts were the main problems. Understand they used them for strength but a little more design effort could have resulted in far longer life. Replaced all and coated with Tectyl 506.

Just a heads up, it is worth removing the plastic upper leg cover (1 small bolt & expands to remove) to see what state the 6 main bolts securing the power head to main leg are in.

Don't know what level of maintainence was put into mine as I bought it 2nd hand but externally it had good appearance and plenty of grease had been used.

Other than the above has been a good reliable motor so far. ;D

[bdm56]

bootyinblue, the sender/oil tank in the 40 and 50 or 2006 v's 2002 must be different as I have taken out and changed the sender unit (metal encased in plastic) with the oil tank full of oil. No leak and the seal is just to keep out salt etc. ;D

[bootyinblue]

Oohh no worries then, the 2006 model has the probe enter the tank, it has a small O ring around the base of it, a piece of poly tube about 1 inch long and which is split length ways to fit snuggly in and then a small self tapper with a washer behind it which pushes on the tube, which pushes on the sender unit which should seal the O ring (or not in my case)

The people saying the tanks leak when full and tilted, it would sugges to me that they are OVERFILLED then...LOL. There is a breather right at the top of the tank next to the filler cap. Push it down to seal if you want to fill your tank up to the brim, just remember to open it again before starting your engine.