First time working on an I/O?

[BLACKATTACK76]

I have a 1989 Maxum with a 5.0 L merucruiser with an Alpha 1 lower Unit. I have worked on many outboards in my life with jet drives, but this is my first time working on an I/O. My issue is I have no water getting to the engines water pump and wondering if the Alpha 1 lower unit has a Raw water pump in the lower mechanic like all the out boards. Also was wondering where I could find a parts diagram of the lower unit, I have numerous outdrive diagrams but no lower units. I was also wondering if the lower unit does have a Raw water pump what all I would have to do to remove the Lower unit.

[Capt Al]

Yes, you'll find the impeller in the lower half of your drive. YouTube has a good demo video if you search "replace sea pump impeller on a alpha- part 1" . If you want the diagram, just Google Mercury Alpha one diagram and you'll get plenty. Good luck.....

[seapuppy]

definitely what capt al said....the impeller is in the lower unit and you need to drain the oil out of the unit and then seperate the lower unit from the upper unit...the impeller is on the top of the unit...be sure to put the drive in fwd before you start working.....

and welcome to the zoo.....

let us know how it goes...

SP

[BLACKATTACK76]

Thanks Capt Al, your suggestions helped out alot. Everything has gone smooth. I have it all apart and the impeller is shot and I am having difficultie getting it off the shaft. I can get it to move up about a 1/4" before it catches, any Suggestions?

[BLACKATTACK76]

Got her off just had to persuade her a little bit know I just have to order the parts and wait.

[mcoffey]

Most marinas will have that stuff in stock since it is so common. If you are ordering online, check out iboats.com, they have good prices and ship quickly. I normally get what I order in 2-3 days here in VA.

[Capt Al]

Yes, marinas and West Marine have them but are a little pricey or you can go on line to save. When you replace the parts don't forget the pesky O ring seal. If not replaced the unit can leak drive fluid. I like to use a little grease on the seal to keep it in place when you close up the drive....

[BLACKATTACK76]

Got the parts in last week and tonight is the first time I have avaliable to work on the boat. I was wondering if there is supposed to be a gap between the Pump Cup and the Pump Housing?