View Full Version : Mercury M2 jet drive 240 stator oil

11-25-08, 12:28 AM
I put my stator on and could only manage to put 600-650mls of HP mercury oil in. I tried from the top drain plug first but that did not work because there was no vent. So I opened both holes and put a hose in the bottom hole. It was very slow to put the oil in by gravity. Finally I simpky blew the oil in. When it started sputtering out of the top hole I put the went plug back in.

I thought I read you need to put in just over 1L ? Has anyone done this before and how much did you put in ?



11-25-08, 12:48 AM
The spec that I have always seen, and from experience changing the oil in mine is 550ml.


11-25-08, 09:40 PM
The proper way to fill your pump drive housing with oil is by removing the bottom plug for fill and the top plug for venting. Like filling the foot of an outboard motor, you push oil in and up till it vents.

The capacity of your pump drive housing is 27 oz. (825cc) and should be filled with High Performance Gear Lube (92-13783A24).

You should also check your stator oil periodically. This is done by removing the allen head plug on the upper side and dipping something like the tip of a scerwdriver in to see what the level is. It should be just below the theads. You should also be looking for contamination, discoloration, milky color from water aeration.

The stator housing holds 19 oz. (550cc).:cheers:

11-25-08, 10:15 PM
:agree: Good idea on mentioning the pump oil as it is separate from the stator oil.

To change the oil in the pump housing, lay on you back and slide under the boat. Directly in front of the intake grate you will see two large slotted screws, these are your drain and fill plugs. The plug in the center is the drain/fill, and the plug off center to the left of the boat is the vent.

Slide a drain pan under the boat, and pull both plugs. Now go have a beer (or two......) for an hour or so to give it time to drain and refill with an outboard gear oil pump or something similar like seadoosnipe mentioned, through the center drain/fill plug.

Note both plugs have a rubber sealing washer on them. MAKE SURE YOU DON'T LOOSE THEM.:cheers:


11-25-08, 10:54 PM
Ok I was bored, so I went and crawled under the boat to grab a couple of pictures.

Hope these help anyone who is running the Merc M-2


11-26-08, 10:05 PM
Aaron, anytime your bored, you just go right ahead and take all the pix you want. We have a place in the forum for all your pix!......:cheers:

11-26-08, 11:45 PM
thanks guys. i did not realize there is pump oil as well. Exactly what does the pump do ? I thought a shaft came down the bottom of the motor and has an axle that turns into the drive shaft that the impeller is attached to? I thought the only oil was in the stator ??

Can you tell me what the pump does ?

I had pumps on my PWC's and now on my boat I thought all I had was a Stator instead of a pump. Please fill me in.



11-27-08, 03:03 PM
Your on the right track Wayne. The Mercury power head sits vertically in the hull with the drive shaft pointing straight down. The pump housing is actually the pinion gear housing that changes the path of power ninety degrees towards the back of the boat.

The stator housing holds the rear support bearing for the drive shaft.


11-27-08, 09:11 PM
Wow, I'm not needed at all in this thread..........:agree:with Aaron. He has obviously done a lot of maintenance on his Merc......

In that bevel gear, where the vertical and horizontal shafts meet, there are bushings. The oil is needed in this pump housing for friction/heat created where the gears mesh together. Unlike a straight shaft in the Rotax driven boats, this is the one huge difference in the Merc pumps verses the Axial flow pumps.

I think I'll bow out of this one. I believe Aaron has a good handle on these things. I def have to add to your reputation Aaron. Great advice and good job.............:cheers:

11-29-08, 06:18 PM
Thanks Aaron.

When should the pump oil be changed ?


11-29-08, 06:25 PM
Once a year, the same as the stator oil. I just do it as part of winterizing. I feel it's more important to change the pump oil, as the oil see's much more abuse from the shearing forces of the gears.


12-01-08, 10:02 PM
Does it use the same oil ?

I guess you need a pump for changing that oil !?

12-01-08, 10:26 PM
It's the same high performance Mercury gear oil as the stator. You will need some sort of pump to get the oil in as you have to do it from directly under the boat.

I'm spoiled, because we have a pneumatic fluid pump at the shop that I borrow when I change the oil in mine, but you should be able to pick up an outboard motor gear oil pump at Canadian Tire or Mobius Marine.

12-03-08, 10:23 PM
cool thanks