Mercury Pro XS 200 Lower Unit

[aking]

Ive heard that you need to change the lower unit oil every 100 hours of use. Right now it only has 68 hours on the motor.

1) How hard is it to change

2) How much oil will it take

3) Never done it

[dannyp]

Nov 27, 2011 15:02:14 GMT -1 aking said:

Ive heard that you need to change the lower unit oil every 100 hours of use. Right now it only has 68 hours on the motor.

1) How hard is it to change

2) How much oil will it take

3) Never done it

Lower unit oil is VERY EASY on a scale of 1-5 with 5 being the hardest this is a 1.

1st) I would get 2 new drain and fill plug gaskets. (Bay or Dalton should have them as they are a very common part)

2) Go ahead and get 2 qts of fluid. Again Bay or Dalton will have what you need. Just tell them what motor you have and they will get you the right fluid. I doubt you will use all 2 qt but at least you will have some on hand for top offs if needed. Also going to need a pump that fits the bottle. They do have this in a small kit.

3) First off so you can have a good idea of where everything is at Raise the motor up as high as it will go.. Now look on the lower unit, towards the front, and more or less on the bottom and you should see a screw (More than likely on the port side). This is your drain plug/screw. Now right above it towards the top is another that looks just like it. This is your check plug/screw. Ok Now that we know where everything is, lets change the oil.

Get a drain pan and set it on the ground below the unit. With a large screwdriver LOOSEN the drain plug DON'T TAKE IT OUT just LOOSEN it. Now do the same to the check (top) plug. Now that you have them loose, lower the motor till its pretty much level. With the drain pan underneath go ahead and 1) Remove the top Check plug and then the Lower drain plug. fluid should be running out.

Inspect the bottom plug, It is probably a magnet and you will see a lot of metal shavings,, thats ok just don't want to see any big pieces. Replace the gaskets on each plug. Inspect the fluid,, if it looks real milky you may have a seal leaking and allowing water to mix with the fluid. This is something you might want to take care of soon especially if you use the boat alot.

Ok assuming everything is ok, open your first bottle and put the pump in it, on the other end of the pump its threaded, YOU ARE GOING TO THREAD THIS INTO THE BOTTOM/DRAIN HOLE!!!!! Leave the top plug out. Once you have it snug pump away until fluid runs out of the top hole. (This is filled from the bottom up to force out any air pockets that would result from a top fill)

Ok now replace the TOP CHECK PLUG AND Tighten it down.
Now remove the pump and replace the lower drain plug.. DON'T GET IN A HURRY AND CROSS THREAD the plug,, Take your time.

VOILA your done. I suggest checking your fluid at least one every 3 months and more if you use the boat on a pretty regular basis. To do this simply remove the top Check plug and see if fluid trickles out or take a small bent piece of wire and stick it in the hole to see where the fluid level is at.. it needs to be within a inch or so of the top,,, if low,, top off and to do that you just do everything you just did here.

Dannyp

[crizzel]

With a optimax or optimax pro xs you have to pull the prop off the drain it(plug is behind the prop). Also when putting the lube in a optimax or pro xs, Once its filled and flowing out of the top plug take your time putting the bottom plug in because optimax/ opti pro xs's lower units build up pressure (let around a ounce come out).. I learnt this the hard way..

[dannyp]

Dec 2, 2011 13:46:40 GMT -1 crizzel said:

With a optimax or optimax pro xs you have to pull the prop off the drain it(plug is behind the prop). Also when putting the lube in a optimax or pro xs, Once its filled and flowing out of the top plug take your time putting the bottom plug in because optimax/ opti pro xs's lower units build up pressure (let around a ounce come out).. I learnt this the hard way..

Thanks Crizz,, Never knew this about the Opti (Course never had one ) Who ever designed it that way obviously never does his own maintenance. I all ways say if the person who designed it had to work on it,, they would find an easier way

[crizzel]

Yeah just a way where marinas can make more $$$

[aking]

Thanks for the info, guess i gotta go buy a prop wrench now huh?