LowerUnit Pump

[San Chan]

Buddy wants to use my pump for the LowerUnit (MErcury90HP, 4 Stroke) to change his Optimax 135 LU oil. Will the screw it fit? Or he have to buy another model to fit his?

[Opti-Mist]

It should be good. They seem to have a standard thread.

[ffishman]

I do believe its the same one. Cabela's sells an adaptor to go to a smaller size if needed. I bought it for changing the lube on my T-8

[San Chan]

Thank you..............

[yarcraft91]

Mercury and Bombardier both use the same size lower unit drain screw throughout their product line. Some of the Japanese brands use a different size and require the adapter.

[San Chan]

Used it yesterday and yes its the same. Thank you.



We managed to drain out ONLY half Quart but have pumped in about 2/3 Quart with the one year old 135 Opti. So Mercury didn't put enough or we put too much? We let it dripped for 10 mins or so.....pretty sure its empty in there. ISn't that strange?

[yarcraft91]

You won't put in too much fluid if you follow the manual's procedure.

Just curious- how did you measure the amount of fluid you drained and pumped in? The difference you're talking about is only about 4 fluid ounces.

[San Chan]

You won't put in too much fluid if you follow the manual's procedure.

Just curious- how did you measure the amount of fluid you drained and pumped in? The difference you're talking about is only about 4 fluid ounces.



It was brand new see~through bottle as we pumped in, thats how we know how much we had and we used another empty see~through bottle to pour the old oil in and it only filled up half.

[yarcraft91]

OK- so you're assuming the volume graduation marks on 2 different bottles are accurate and that all the old fluid actually got into the second bottle. You probably saw a real difference between how much you drained and how much you pumped back in, maybe less certain how much difference.

I've never checked how accurate those bottle graduation marks are, but expect they are only approximate. Looking at two near-identical bottles in my garage, just different brand names, I find the graduation marks do not line up between the two bottles.

[Pezman38]

I just used a pump for my 225 Opti and was curious to what brand works the best? The one I used was less than ideal.

[yarcraft91]

I bought one this year with the Mercury brand name on it- I thought it worked better than my old OMC-branded pump.

[San Chan]

OK- so you're assuming the volume graduation marks on 2 different bottles are accurate and that all the old fluid actually got into the second bottle. You probably saw a real difference between how much you drained and how much you pumped back in, maybe less certain how much difference.

I've never checked how accurate those bottle graduation marks are, but expect they are only approximate. Looking at two near-identical bottles in my garage, just different brand names, I find the graduation marks do not line up between the two bottles.




yea......maybe they are not accurate. Will pay closer attention next year.

[Brookieslayer]

you have to pump it in until it comes out the top screw. don't worry about measuring what goes in and what comes out, pay more attention to the colour of the oil coming out. Hope this helps, that 135 should almost take a whole litre of oil.