How to replace the impeller on a Mercruiser Alpha One sterndrive | My Boat DIY

In this DIY feature, Steve replaces the impeller in a Mercruiser Alpha One sterndrive. Not quite as easy as the Bravo 3 with its remote water pump, the Alpha pump is located in the lower unit, which has to be removed. But with a few common tools and a few tips, you can do this yourself. Don't forget to keep a spare onboard, just in case!

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This segment was featured in an episode of PowerBoat Television.
PBTV-2018-E12

#impeller, #mercruiser, #alphaonesterndrive

[jenniferfrajerman]

I had my impeller replaced before the season and had lube oil leak all season. Any chance as gasket was missed and these are connected ? Thx

[jeffstreet]

I have done this three times by myself. It is a pain in the ass. This video doesn't even come close to giving all the detail and little tricks you actually need to know. You will find out on your own though. Look at several other YouTube videos before doing this.

[leonelfrydman]

Very good explanation. Now, how do I know is the impeller? The boat was smoking. Thank you

[stretchi]

What fell out when you removed the lower unit from the boat? Was it one of the exhaust flappers? Just curious because I bought a new to me boat last year that had been overheated. I’ve done the head gasket and replaced all exhaust bellows and it runs good. Going to replace the impeller in a few days this year just because. When I replaced the exhaust bellows (merc 3.0), I installed a new flapper because the old one was gone. Don’t know where the pieces went. The exhaust bellow between the boat and drive was completely separated when I purchased the boat so the pieces may have exited before me. If they haven’t by chance, would I find them when I separate the drive to replace the impeller-if they’re in the drive somewhere?

Thanks for any advice!

[johnjaymesgreatadventures]

Nice video! Short & Sweet and to the piont! 🤙

[nm]

"Out with the old, in with the nucleus." I recognize that from The Simpsons episode "Homer Goes to College".

[kriegdg]

Can anyone just tell me the part number for this kit or the best kit to get. Opening a Alpha One on a 1990 stingray that I just want to tear down and replace once everything versus just the impeller. Appreciate the addition insight of the comments.

[eduardoconde]

Dude, you missed the boat.

With the production quality, you could've taken the time to talk about the 6 bolts, location, needing to remove the bottom anode plate (but not the top one, like you did on 1:35), etc. This could've been an awesome instructional video.

Why not record a new one where you take the time to walk us through?

[grommdk]

think you did miss a important part - the sealer for oil between upper and lower part...? ;)

[dansportdr]

The 'fill' plug for my lower unit is above the flange. I assume I need to drain the gear lube before removing the lower unit?

[marcusi]

Just bought an impeller kit yesterday, and this gem comes out. Is it absolutely necessary to apply sealer? it looks like the mercury genuine kit that I bought has a silicone bead on the gasket already.

[mikeedwards]

Why doesn't anybody show which way to put the impeller back in. It's got to go a certain way

[leonelfrydman]

I removed the lower unit and oil come out

[soccaplaya]

Bad video all the way around.
-Didnt mention removing avoid
-Didnt mention draining lower unit
-Do not use silicone
-Rotate impeller when reinstalling to mesh up groves
-You mentioned nothing about the splined shift at the front that needs to be aligned into color.
-always a good idea to use a little oil on rubber impeller

All around the only useful part of the video was to have it in drive. By yourself, never had done it, this should take no more than an hour.

Why did you even make this video?

[loaforious]

Below is a more accurate how to video. 👍

[hughrobertson]

Short and not so sweet. Failed to show any of the tricky little steps (or the big one-draining the oil before dismantling!) complete waste of time.

[kevinpiazzisi]

It's almost like you are afraid that a group of marine mechanic is going to Kick your A**. This is a simple repair by anybody, end of story.