Water pump installed but with new question

dgjones

Seaman
Joined
Mar 2, 2010
Messages
62
First of all I want to give a big thanks to everyone that guided me to installing a water pump on my 1973 evinrude sportwin 9.5. I got the lower unit off with ease thanks to your help. I did not realize that the water pump fit so tight inside the housing, its almost impossible to turn by hand once it is in the housing. After I installed the water pump and put the lower unit back on I pulled the engine over. I have not run the engine, but it seems harder pulling the engine over after I installed the new water pump. Does it just need a minute to run to soften up the water pump so it spins easier? Also, the water pump I installed had straight fins. The old pump that I pulled out had curved fins. Do the fins go from straight to curved after being in the housing for some time?
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Water pump installed but with new question

Ahhh --- yup. Did you not have to bow the fins a bit to install the impeller? If any part of your body had to sit in a bowed position for years at a time you would have some bent body parts as well. Same principle applies. The impeller is bigger than than the housing so something must bow and the fins are it. That's what makes the pump work.
 

RadarRick

Petty Officer 2nd Class
Joined
Jun 30, 2010
Messages
189
Re: Water pump installed but with new question

Make sure to run it in water. Running dry will destroy the new impeller.

The new impeller does have straight fins. They will bend in time.

Some people put a small amount of grease or detergent on the impeller when installing.

As long as you're confident that you've used the correct impeller, you should be ok. Running in water will lubricate it.
 

Sixmark

Master Chief Petty Officer
Joined
Jul 11, 2010
Messages
890
Re: Water pump installed but with new question

Make sure to run it in water. Running dry will destroy the new impeller.

The new impeller does have straight fins. They will bend in time.

Some people put a small amount of grease or detergent on the impeller when installing.

As long as you're confident that you've used the correct impeller, you should be ok. Running in water will lubricate it.

They better bend when the impeller is installed or it's the wrong size impeller, the cup formed is what supplies the proper amout of flow.
 

kenmyfam

Supreme Mariner
Joined
Aug 10, 2006
Messages
14,398
Re: Water pump installed but with new question

Need to bend to work and pump. I always use a little dish soap to lube it up to begin with.
 

dgjones

Seaman
Joined
Mar 2, 2010
Messages
62
Re: Water pump installed but with new question

Ahhh --- yup. Did you not have to bow the fins a bit to install the impeller? If any part of your body had to sit in a bowed position for years at a time you would have some bent body parts as well. Same principle applies. The impeller is bigger than than the housing so something must bow and the fins are it. That's what makes the pump work.

No I definetley had to bow the fins to get it to fit. I was just suprised at how much friction there is between the impeller and pump housing. I guess that's why you never run it out of water lol!!! (and i never will)
 
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