Which water pump do I need?

[18Tahoe550tf]

Can anyone direct me to the water pump/impeller/gasket kit I would need for a 2018 OptiMax ProXS 175, serial number 2B402162? I'm looking around online and can't seem to find a complete kit, only individual parts.

[JOE54]

get 89984T5 and 96148T1 all you need

[SilverFox579]

Forum sponsor European Marine has kits - If you want to order or price Mercury Engine Parts or Accessories

[EuropeanAM]

96148A8 is also a good option (everything you need in one part number).

[18Tahoe550tf]

Thanks everyone

[JOE54]

[18Tahoe550tf]

I installed the 96148A8 kit today. This was my first water pump install ever and things went pretty well overall although I had some trouble with the shift shaft lining up during reassembly despite having it in the Fwd position from the start. I was surprised that there was not a seal for the top of the pump housing for the drive shaft. Is this normal for this motor? At idle I was getting 1-2 psi and at WOT about 12 psi before the pump change. Now it's about 5 psi at idle and 20 psi at WOT Which seems high from the info I've seen on here. Are these numbers good? Will they drop a little as the impeller wears in a bit? Was also surprised to see quite a bit of what looked like caulk around the back of the original housing where the exhaust is. Is that something that would have been used during the original assembly of the motor? This is the first time it's been taken apart to my knowledge as I am the first and only owner of the boat.

[leonreno]

The pressure will drop as the impeller sets in, your numbers are normal. That caulk is used to prevent exhaust gases from overheating the water pump, technically should be replaced each time but in practice it seems to hold for a couple of disassemblies. You can use RTV silicone sealant or other high temp sealants.

[JOE54]

+1

[18Tahoe550tf]

Thanks again!

[SilverFox579]

Here's a tip for the next time you service the water pump, leave engine in NEUTRAL and do not rotate, then after you remove the lower unit but before you start disassembly, wipe the shaft clean with lacquer thinner, brakeclean, etc. and make an index mark (Sharpie works well) as shown in the picture below. When you're finished with the lower unit simply rotate driveshaft to align the mark, slides right in.

The 2.5L does not use a seal above the pump housing and the caulking is the exhaust dam. I replace the exhaust dam with high temp RTV every time I service mine.