Getting ready to do the impeller on a new to me Pro XS 250

[smav]

I'm getting ready to do the impeller (have the kit with the housing already, so we'll see how it looks and may replace as well) and have watched several videos on impeller replacement and also read as much as I can on the Boards. My motor SS is 2B111222 and is a 2014. In one of the videos it showed using black silicone sealant on the lower unit on the exhaust divider block (I think that's the correct term), but most of the videos and written instructions don't mention or talk about it. Is that step necessary?



Haven't taken the gear case off as of yet, but wanted to be as prepared as possible for when I do!

[Champ 2001]

I don't think it's required per the manual, but I have been doing that on mine when changing out the the water pump.

[EuropeanAM]

Steve: Welcome to BBC, and Thank You for having your information handy!

I would strongly recommend that you take the toobe videos and either forget most of them, or go with the approach that there's something hidden in each one that you should NOT do.

Many of those things are riddled with errors... the BEST guide for servicing your outboard would be a Factory Service Manual.

See "Sherm's Tips" for Water Pump Replacement in the FAQ Section. They're spot on with just TWO exceptions:

1. I recommend having the control handle in NEUTRAL (not in forward).

2. Use DAWN DISHSOAP as the lubricant to install the impeller into the housing. NEVER use gease, oil or any petroleum product on your impeller.

[smav]

I don't think it's required per the manual, but I have been doing that on mine when changing out the the water pump.

So when I do it again in the future, I'd also need to scrap off the old silicone and then reapply each time?

[Champ 2001]

So when I do it again in the future, I'd also need to scrap off the old silicone and then reapply each time?

That's what I do. I actually got the idea to do this step on this forum in the FAQS. Someone put together a step by step procedure included with photos. I figured it wouldn't hurt and so far it hasn't.

[JOE54]

you guy know why thats done ?????

[Champ 2001]

you guy know why thats done ?????

Well not 100% sure, but the last time I changed mine the gasket was torn and protruding outside of the housing assembly.

[JOE54]

the silicone does 2 things it helps retain water that is dumped on the water pump housing from above , keep exhaust from blowing in on housing heating it up

[SilverFox579]

the silicone does 2 things it helps retain water that is dumped on the water pump housing from above , keep exhaust from blowing in on housing heating it up

Yep!

There's a very good FAQ topic for the 1.5L Opti water pump service with lots of pics that is the same, or very nearly so, as the 3L. The 2.5L engines are different.

1.5L (75-125hp 3 cyl) Optimax Water Pump Replacement

[Champ 2001]

the silicone does 2 things it helps retain water that is dumped on the water pump housing from above , keep exhaust from blowing in on housing heating it up

[smav]

Is there a Mercury part number for the Face-Seal setting tool? The kit I bought didn't have the tool and I can't find a Mercury part number anywhere. I guess my other option is to push the face seal down the shaft until the top of the seal is .350" from the top of the housing? With the .350" height, I assume the seal is touching the housing, but not where the seal is pushed down into the housing?

[JOE54]

serv manuel page 6b-63

[JOE54]

serv manuel page 6b-63

818769

[smav]

Thanks! I saw that number in one place, but wasn't sure if Mercury made different one's for different lower units. Thanks for confirming!!

[JOE54]

you can just measure it too

[EuropeanAM]

And the seal will seat ATOP the housing (not down inside).

If you order a kit from Rhonda- you can always request an extra face-seal tool. Be glad to throw one in for you.

[bhjr.]

Just did mine today. Super easy, especially if you use two studs to align the housing as you slip it down over the impeller. That tip is in the stickies.

[JOE54]

821571A1 alignment pins

[smav]

Got the impeller and the rest of the kit (housing, etc) installed yesterday afternoon. I think the hardest part was getting the lower unit off after loosening all the bolts as the LU was stuck on the top of the bolts and took some coaxing to get off. Then took a little bit to get the snap ring off of the carrier assembly oil seal and then getting the carrier installed back deep enough to get the new snap ring back on (had the LU vent plug removed). Next issue once I had the new impeller on and then everything button back up, reinstalling the LU was a bit of a chore trying to get the speedo water line connected back up while holding the LU in place. Used a jack to hold the LU up high enough to get a pair of needle nose on the hose to get it pushed back in to the LU.

After that, smooth sailing!! I greatly appreciate all the help from the Board!!

Next will be the spark plugs, fuel filter and cleaning the water strainer!

Anything else I should look at while I'm at it?

[JOE54]

heres a tip, next time install speedo tube last if you look in hole you can see legris fitting thats why they put hole for hoe s , just stick hose straight down in hole nutn to it ,you can also remove hose before removing case ,depress fitting with small screw driver and pull on hoe s , also install coupler on top of pump on copper tube first before case install , copper is sharp can cut o ring doing it that way good luck JOE