Mercruiser Service

[SOLER]

I have a Tahoe boat with a mercruiser. It has a 4. 3 Liter V6. It is overheating and I think it is the impeller. Does anyone know how to take these apart? I am looking for a service manual, but every store is closed now, and I've got parts laying around. I'd like to finish tonight. Does anyone have pics and instructions?



Thanks!



SOLER

 

[kentdiesel]

I don't have pics but I can give you instructions on taking lower unit off of a .

Alpha 1, 1st generation outdrive:

Engine off.

If you have a low trailer you may have to tilt oudrive back to gain clearance for removal.

Drain gear oil.

Push throttle forward (in gear) all the way.

Remove little fin above prop by removing plastic plug above fin so you can get to the 3/8 allen head capscrew that holds fin on.

Remove nut under fin.

Beside fin there are two nuts in a recess you have to remove.

On side of outdrive where lower unit separates from upper unit there are two nuts to remove.

In front of lower unit there is one nut to remove.

Grab lower unit and wiggle it and it will drop down from upper unit.

Water pump can be serviced now.

To reinstall you can turn propshaft by hand to line up splines.

Use mercruiser outdrive oil only.

 

[SOLER]

I think mine is a little different than what you described. But, if I get a Seloc manual, is this a difficult job? How hard is it to get it apart, replace the impellar, and get it back together without screwing anything up?

 

[CumminsBu]

It's not hard just take your time. Kent pretty much summed it up.

 

[TORQUE THIS]

Mercruiser engine and sterndrive help and assistance

You'll need a bellhousing gasket kit also...

The above site has a lot of great how-to's...

 

[SOLER]

Mercruiser engine and sterndrive help and assistance



You'll need a bellhousing gasket kit also...



The above site has a lot of great how-to's...

This was the site that scared me from doing it. I usually do ALL of my maintenance, but this one sort of shyed me away.

 

[TORQUE THIS]

Yeah, they make it sound worse that it really is.

You can just drop the lower unit without removing the drive from the boat also.

There is a small gasket that goes on the oil passage between the 2 halves. If you forget this, it is going to leak.

Making sure the drive is in forward is a PITA also. When you shift into forward, you don't need to push it to WOT, that is not necessary.

I replace the entire pump every season. It's about $60 for the upper, lower housings and all the gaskets.

When you install the pump impeller, make sure you soap it up really well. And rotate the drive shaft clockwise while putting the pump housings together.

And NEVER run the boat without flush muffs on the drive. Crank up the hose, it will spray water all over, better to have too much water that not enough and smoke the new impeller. Also, when you first start it, get the RPM's up to 1500 for a few seconds to make sure you get good water flow.

 

[SOLER]

Thanks y'all. I'm going to go get it back from the dealer tomorrow and do it myself. It'll save about $300! That's two tanks of precious diesel! (it used to be 6 tanks worth)



SOLER

 

[SOLER]

Well, I called 'em yesterday morning, and they had already started on it. In a way that's good. They said it would take a week, and they got to it in two days. They also noticed that the plastic water supply tube was melted and are waiting for the part.



I will definitely be checking this myself every two years and never again run the boat without the bucket or the flushing device.