Repairs for Most Yamaha Water Pumps

Yamaha Water Pumps

Introduction: Instructions for Yamaha Water Pumps

Yamaha puts out basically the same water pump for their Yamaha engines. You can use these instructions for most Yamaha outboard motors. Some Yamaha outboard motors may be slightly different but basically the same.
These instructions are a good guide to installing and reinstalling the Yamaha outboard motor water pump.

Yamaha Outboard

Pt1 Yamaha F250 Water Pump Impeller


Pt2 Yamaha F250 Outboard Water Pumps Impeller Repair

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Yamaha Outboard Motor Water Pump Repair


Put engine in neutral. Rotate your propeller by hand to make sure. If it easily turns round and round, it is in Neutral

Step 2

Unbolt the lower unit cowling. Remove all 6 hex bolts to prevent damaging the cowling.

Step 3

Be careful with the "tab nuts" that may fall out of the slots in the
Cowling. The tab nuts are located in the 2 bottom holes on the front part of the

Step 4

Pull out the rubber plug for accessing the trim tab bolt.

Step 5

Tilt the outboard motor up then remove the prop.

Step 6

Take a note of the location of the tab.

Step 7

Unbolt the trim tab bolt.

Step 8

Unbolt the two bolts under the lower unit.

Step 9

Remove 6 bolts from the lower unit, 3 on each side.
Source: http://Dusty.crockett at en.wikipedia [GFDL...

Step 10

Mover lower unit up and down while pulling outward; Until the lower unit is free. Note: There is no speedometer tube that you have to disconnect.

Step 11

Use a workhorse for a stable platform to perform the

Step 12

Unbolt all 4 water pump housing bolts.

Step 13

Remove the housing.

Step 14

Remove the o-rings.

Step 15

Take off SS driveshaft cover. Use a large screwdriver and pry the screwdriver around
the cover.

Step 16

Slide your plastic compression ring off.

Step 17

Take off the SS impeller housing.

Step 18

Remove the three SS washers. Keep them in the same order to re-install.

Step 19

Unbolt and remove the impeller.

Step 20

Remove the woodruff key. Use an awl, worked perfectly.

Step 21

Take off the SS bottom plate.

Step 22

Peel off the gasket.

Step 23

Clean off all gasket material. Clean the area of gasket material.

Step 24

Pull out old dowel pins.

Step 25

Replace with the new dowel pins.

Step 26

Replace with the new gasket.

Step 27

Replace the new bottom plate.

Step 28

Replace the new woodruff key.

Step 29

Replace the new impeller. Make sure the side with the dots is up, and slashes are down. Slide the new impeller down the shaft and align the slot in the impeller with the key. Push impeller all the way down with your hands.

Step 30

Clean and replace the SS washers.

Step 31

Put the new impeller housing on. Put some grease around the
walls of the housing. Use one hand to bend the fins of the impeller while
push down with the other hand. Note: The shaft turns
clockwise, so the fins are bent. The center of the bottom of the housing should be pointing to about 4 o'clock if you look at housing from the prop-end of the lower unit.

Step 32

Clean and replace the plastic compression ring.

Step 33

Clean and re-install the SS driveshaft cover. Use your adjustable wrench
for this. Open up the jaws of your wrench until it clear's the
Driveshaft, then let it rest on the SS cover then use a hammer to tap it down.

Step 34

Clean your Yamaha outboard water pump housing. Apply a little grease to the slots for your o-rings to help hold o-rings in place.

Step 35

Replace your water pump housing. Make sure the o-rings stay in place. As you
slide the housing down, rotate the driveshaft while aligning the impeller housing
with the pump housing until it slides down over the dowel pins.

Step 36

Smear some anti-seize compound on new bolts.

Step 37

Apply some grease to all the fittings for water pump inlet and
your speedometer tube. Apply grease to the driveshaft splines and shifter

Step 38

Blow out the speedometer tube. Unplug the tube from the back of the speedometer and use your air-compressor to blow out debris.

Step 39

Reinstall the lower unit in the reverse order. Before putting all the bolts
back, check the prop shaft to make sure it turns freely so that the shift rod
did not move while you were sliding the unit back on. If the shift rod does not spin
freely, or if you hear a "clicking" noise, the shift rod is out of alignment. you will have to remove the lower unit, adjust the rod, and re-install your lower unit. When the shift rod is in the NEUTRAL position, the prop should spin FREELY. Apply some anti-seize compound to every bolt.

Step 40

Before replacing your prop, Take your thrust washer off to inspect it for
wear, replace thrust washer if you see wear. Grease your prop shaft splines.

And you are finished!!

Tips for Your Yamaha Outboard Motor

Use Green Marine Grease on the shifter splines, the drive shaft splines, and the prop shaft.

Lower unit should drop right down with little effort and go back up the same way

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Sources for Yamaha Water Pump Help

Yamaha Water Pumps Repair Made EasyHere are some really great instructions for how to repair your Yamaha outboard water pump. You will see a great photo illustrations of the tools you will need and the parts you will need to repair your Yamaha water pump.

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