Changed my Impeller...now have questions!

[seadoons]

I got the boat out of storage this weekend after it had been there about 8 months. Put on the muffs and fired it up - and realized that it wasn't sucking up water. Funny the temperature gauge never really spiked but I think that is because it measure the water temp...and with no water there is nothing to measure.

Anyways - I changed out the impeller only. I see videos online of people replacing gaskets and other parts. Should I have done that as well?

Mercruiser 5.0 MPI wth Alpha 1 Gen 2.

[Bald Mike]

It will measure temp...water or no water.

Typically just the impeller needs replaced, unless you overheated.

[Mark-P]

How did the old one look? When ever I did it on my outboards they look good. Wondering if I am to preventitave sometimes.

[Raeburn]

Sometimes the impeller housing gets worn with the impeller and needs to be replaced too (or no water flow - at least on bravo legs)

[seadoons]

The impeller housing is metal and it looked good. The impeller itself looked surprisingly good as well...all of the fins were in place. They were all curved...but that is how they sit in the housing. I know this is a hotly debated topic but I think I will pro-actively change mine out every two years going forward.

[nhsd]

Originally Posted by seadoons

I got the boat out of storage this weekend after it had been there about 8 months. Put on the muffs and fired it up - and realized that it wasn't sucking up water. Funny the temperature gauge never really spiked but I think that is because it measure the water temp...and with no water there is nothing to measure.

Anyways - I changed out the impeller only. I see videos online of people replacing gaskets and other parts. Should I have done that as well?

Mercruiser 5.0 MPI wth Alpha 1 Gen 2.

I just did mine a couple weeks ago and the impeller kit I bought came with new gaskets and o-rings (not the housing or the plastic water line guide), so I went ahead and changed them. Probably would not have hurt anything to not have done so as none of these items appeared worn. However, the gasket directly below the housing would be the most likely to have had an issue if not changed.

[shoestring]

I do mine every year. I get the kit that has all of these parts:
Impeller
Key
Stainless housing liner and plates
Gaskets
Pickup tube o rings
Gear lube passage o ring
Shaft grommet
Drain and vent screw washers.
About $55 if I remember.
I run about 100 hours a year and the impeller comes out looking like new. Some might call it overkill but for me it is cheap piece of mind.

[Raeburn]

The impeller wears grooves into the metal housing. Sometimes when you just replace the impeller, it doesn't seal properly to the worn housing and you dont get enough water flow at idle. I had this happen and had to replace the entire pump housing $$. Something to look out for...

[seadoons]

Thanks for the info. Frankly, I was in a bind as we are planning to use it all weekend this coming weekend...Memorial Day. The marine shop that is close to me...30 minutes away...had the impeller only (not the entire kit). I ran it on the muffs at idle and it cooled just find - in fact it seem to run about 5 degrees cooler than before. I might try to find full kit online and service it at the end of the summer with all of the other annual maintenance that I do.

[Nate S]

Do you remember putting the key back in?