Impeller Change on a 1998 Nautique

[1998CanadaNautique]

Anyone walk me through it?

Thank You

[coloradonautique]

What engine? GT-40 LH rotation?

Here is what I do. May not be the best plan but it works for me.
1) Loosen then remove upper 1/2 inch hex bolt (you can sometimes align the holes in the pulley to get to the bolts easier)
2) Loosen and remove lower 1/2 inch hex bolt
3) Push pump towards engine and remove belt
4) Pull pump away from engine and around engine mount
5) Loosen and remove three 7/16 inch hex bolts holding pump together
6) Pull pump apart, make sure you don't loose the spacer plate or shaft key.
7) Remove impeller that is probably still stuck in the housing.
Note: You never removed the intake or exhaust lines so your chance of re-installing the pump backwards is non existent. If you can't perform step 4 with removing the water lines, try only removing one line instead of both or clearly MARK the lines somehow.

Install:
Note the rotation during dis-assemble.
1) Make sure key is centered correctly on the shaft.
2) Insert new impeller into housing with slight twist in the direction of normal rotation.
3) Install new O-ring
4) Install spacer plate (this is important, see my recent post of what happens when you forget this step)
Yellow_Flash_Colorz:
5) Install new gasket and then insert pulley side of body with shaft and key into impeller/housing side.
6) Align body, install and tighten three 7/16 pump body bolts. Make sure gasket and O-ring are not pinched.
7) Re-install pulley belt, make sure it is in the groove on all three pulleys (pump, flywheel and lower roller?).
7) Pull pump around mount, install lower 1/2 hex mount bolt to finger tight.
8) Install upper 1/2 mount bolt, tension belt to 1/4 inch deflection and tighten upper bolt.
9) Tighten lower bolt.

Fire it up and make sure you have water flowing through the strainer and out the exhaust. Check the belt tension after a couple of hours of run time.

You should be good to go...

Anyone have modifications/suggestions to the above.

-Lorin

[TRBenj]

Those instructions are pretty good. I like to get the pump completely out of the boat to make it easier to work on, and Im not dropping parts into the bilge. I have a mark on the top of my pump so I know its not backwards when I reinstall it.

I also have a mark that shows how the 2 halves of the pump align. It really can only go one way, but its not obvious once you get it apart.

When reinstalling the pump in the boat, you want to make sure the pulley is square (not cocked at an angle) and the belt tension is OK. IIRC, about 1" of deflection (both top and bottom) is about right.

[coloradonautique]

TRBenj,
My 2001 CC manual states 1/4" for both alternator and water pump belts. I wonder if it is different for the pre-GT40 engines? Not sure what the GT-40 service manual calls for.
Good idea marking everything. It is awfully easy to drop parts into the bilge if you are not careful. Actually happened to me this spring and I was baffled as to why my pump would not work for a while.... I found it works better when you actually re-install the spacer plate after taking out the impeller for the winter. Yellow_Flash_Colorz:

Snow here today.. what the ????

[TRBenj]

My 2001 CC manual states 1/4" for both alternator and water pump belts. I wonder if it is different for the pre-GT40 engines?

Youre right- 1" is way too much. I guess I didnt remember correctly- thanks for the clarification. There should be no difference between any of the PCM 351w's.