How difficult is it to change a water pump on a Mercury?

Question

I'm buying a motor, but it's been sitting for a year and the water pump needs to be replaced.

How difficult is this to do? I've never worked on a motor before.

The motor is a 40 hp Mercury (2 stroke) from 1997.

What other maintenance should be done?

Answer 1

That depends... will the motor be attached to a moving boat at the time?

Answer 2

Not a hard job but a few things to be concerned about. The stainless steel bolts in the lower can sometimes be stuck and hard to remove without some type af penetrate oil. Also remember to remove the shift linkage . You might have to shift gears to get it back connected. When installing the rubber inpeller, be sure you turn the shaft in the correct direction when installing to avoid damage when the motor starts up. The water pump tube ( maybe brass )will have to be inserted carfully before the lower will come together for a final fit.

  I would open the carb drain screws and run some gas through before starting to remove any old gas or gas residue. Lower unit oil should be checked by removing the lowest drain s***w and observing what comes out. If it looks contaminated, Drain and replace. Check again after your first river run or outing to determin  if seals are bad.  Good luck

Answer 3

Its very easy. You unbolt the lower unit and if you can put it in a stand. Unbolt the water pump housing and lift it off the drive shaft. Have the rebuild kit ready. Replace all the pieces the way they came off. Grease the splines on the drive shaft and put it all back together.

Answer 4

why go to the trouble of doing this yourself?You SHOULD have the manual that you can buy from the dealer(your going to get the parts from him)The  total price of having the dealer do this for you should be less than $80.00 and you will receive a warranty on the parts and labour.