Impeller questions

Joe

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Step 1. Order the pump kit for your motor, it will come with a new impeller, gaskets, etc.
step 2. Put the throttle in reverse, it is easier lining up later.
step 3. Remove the 4 or 5 nuts holding your lower unit to the upper/middle unit.
step 4. Either ask a buddy for help catching the lower unit, or just leave a nut, or two, loosely threaded. Grab a rubber mallet, or a hammer and wood block, and lightly hit the lower unit. Don't hit it hard, like pounding in a nail, or chunks of aluminum will break off. Just tap it enough and the lower unit will fall loose.
step 5. Once loose, it will weigh the same as a bowling ball, and will be hard to balance. Follow the long shaft and you'll see a cover. Remove the 4 or 6 bolts holding the cover, and slide the cover off the shaft. Take a picture of what the impeller looks like inside the cover, or note the direction the fins are pointing.
step 6. Remove the gaskets you have replacements for, and replace them with the new one.
step 7. Apply a little grease with your finger, on the inside of the impeller cover. Then install the new impeller inside the cover, so the fins are pointed in the same direction as the old impeller.
step 8. Slide the impeller and cover back over the shaft, and tighten the bolts.
step 9. Find the plastic/rubber coupling and make sure it is either attached to the tube on the motor, or the little nozzle coming off the impeller cover.
step 10. Slide the lower unit back onto the motor, and get a couple of the nuts started, then evenly turn each nut until tight.
step 11. Take it out of reverse, put water muffs on the water intake, turn the hose on, and fire up the motor.

if done right, water should come out of the pee hole and exhaust. If that doesn't happen, immediately shut it down, remove the lower unit again, and make sure the coupling lines up. Then the next step is replacing the thermostat, which is usually as simple as removing two small bolts.
 


BGH

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We just changed one on our 150 Yamaha. Pretty simple fix...and I know nothing about boat motors. If I can complete, you should have no problem...ha!!
 

guywhofishes

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Is it better to buy just the impeller or the whole pump kit?

the whole kit - it has new gaskets, wear plates, etc.

although when I changed mine everything, including the impeller, were prestine even a decade old

I think if mud/sand/gravel is often experienced with your style of fishing then a kit is mandatory

but if you "baby" your cooling system because it's only weeds/water that ever make it into your pump then I think impeller only would be fine because you're just maintaining the flexibility of the impeller blades (not repairing true wear/tear)
 

Sub_Elect

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The sand in the Missouri River eats water pumps and parts quickly. Replace it, it's easy.
 


eyexer

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I would do the whole kit. not much more money and as mentioned the sand here kicks the housings butt
 

Retired Educator

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Step 1. Order the pump kit for your motor, it will come with a new impeller, gaskets, etc.
step 2. Put the throttle in reverse, it is easier lining up later.
step 3. Remove the 4 or 5 nuts holding your lower unit to the upper/middle unit.
step 4. Either ask a buddy for help catching the lower unit, or just leave a nut, or two, loosely threaded. Grab a rubber mallet, or a hammer and wood block, and lightly hit the lower unit. Don't hit it hard, like pounding in a nail, or chunks of aluminum will break off. Just tap it enough and the lower unit will fall loose.
step 5. Once loose, it will weigh the same as a bowling ball, and will be hard to balance. Follow the long shaft and you'll see a cover. Remove the 4 or 6 bolts holding the cover, and slide the cover off the shaft. Take a picture of what the impeller looks like inside the cover, or note the direction the fins are pointing.
step 6. Remove the gaskets you have replacements for, and replace them with the new one.
step 7. Apply a little grease with your finger, on the inside of the impeller cover. Then install the new impeller inside the cover, so the fins are pointed in the same direction as the old impeller.
step 8. Slide the impeller and cover back over the shaft, and tighten the bolts.
step 9. Find the plastic/rubber coupling and make sure it is either attached to the tube on the motor, or the little nozzle coming off the impeller cover.
step 10. Slide the lower unit back onto the motor, and get a couple of the nuts started, then evenly turn each nut until tight.
step 11. Take it out of reverse, put water muffs on the water intake, turn the hose on, and fire up the motor.

if done right, water should come out of the pee hole and exhaust. If that doesn't happen, immediately shut it down, remove the lower unit again, and make sure the coupling lines up. Then the next step is replacing the thermostat, which is usually as simple as removing two small bolts.

Good explanation. Pay attention to #2. Not having it in gear makes putting it back together a real PITA. Other than that it's pretty straight forward. The advantage of changing frequently is that they are relatively inexpensive and it can be done when the water is hard if you have a place to work on the boat.
 

Lou63

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oh one thing I have learned to use my cell phone for it take pictures before, during and after so that if you are scratching your head looking for where that extra seal goes

oh and get the medium strength loctite for your bolts and I had the blue silicone gasket stuff to hold in the seal around the cap for the impeller.

I was lucky enough to have a small picnic table bench with a gap just right to put the skeg in so it was balanced and stable to work on.
 

Ericb

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I do it whenever my mechanic suggests it. Couldn't tell you how often or when the last time I had it done. For me it's cheap insurance to not having a bad day on the water or have to miss a day of fishing during the season. If I bought a motor and didn't know when it was done last I'd just get it done and not have to worry about it.
 


NSSJ

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One more thing you might try, take the hose off the pee hole and use your air compressor to blow the crap out of the water jacket. Worked on my 4 stroke Yamaha
 

bigbrad123

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One more thing you might try, take the hose off the pee hole and use your air compressor to blow the crap out of the water jacket. Worked on my 4 stroke Yamaha



I did that. Even soaked the hose a bit in some CLR. The hose was completely clear. Water ran through the hose well after that when I had it under the faucet in the house. Figure it must be the impeller. Ordered the new pump kit yesterday and hoping to do it this weekend.
 

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