2004 21i impeller

[davidmamato]

I am looking for part # for impeller and helpful tips on when and how to change? thanks

[boatwakes]

Please post engine manufacturer and engine serial number.

[huntingwiley]

If you have a Merc 350 Mag MPI it is going to be:
IMPELLER : 47-59362T 1

It is pretty easy to change. I change mine at the beginning of every season. I have an 03 21i.

[davidmamato]

350 Mercruiser, I will try to find engine serial #

[davidmamato]

thank you huntingwiley!

[davidmamato]

serial # om394888

[davidmamato]

I provided the engine serial # is 47-59362t 1 the correct impeller? Thanks

[TeamAllen]

Looks like Part #: 47-862232A 2 to me?
http://www.perfprotech.com/mercruise...r/umodel/10718
http://www.perfprotech.com/mercruise...0?umodel=10718
http://www.perfprotech.com/mercruise...product/186958

[Formulaz]

My ser # is 0m312790

Impeller has been changed.

Do you suspect that I used the wrong part? It was looked up via serial number and seemed to compare exactly to the old one

[Formulaz]

Oops sorry wrong thread

[davidmamato]

47-862232A 2 is the correct impeller for my boat THANK YOU, THANK YOU Mike Allen for saving me from the hassle of getting the wrong impeller. Mercurymarine.com is a little confusing using the serial # search. Once again this website has been very useful. I thought about not replacing the impeller this year, but good thing I did because one of the legs of the impeller was cracked. I am now going to replace the impeller every season. It only took about 1 hour and it was pretty easy.

[boatwakes]

FYI, the difference between the two is in the drive, the first part number is referred to as a "D" drive or single flat. The pump you have and the impeller that goes in it uses a double flat drive and neither will allow the installation of the incorrect impeller. All of the impeller length problems, and subsequent overheat issue upon initial start up, are on the crankshaft driven pumps. Be sure the o-ring in your raw water pump is either still re-usable or replaced correctly. Look for corrosion, seal expansion or bearing failure/water seepage while the pump is apart to avert more issues (for everyone else reading doing their own service).