1994 Merc 7.4 Carb impeller Kit

[tonyiiiafl]

Does anyone have the part number for a replacement impeller kit for the gen 5 merc 7.4 belt driven (fuel pump on top) raw water pump? I have a spare new pump, but it has been in the box for a year now, so I thought I should replace the impeller before installing. I replace them as per Merc recommendations of every 3 years. I swapped out the starboard one last year, will do the port one this year, and have a year off next year. A lot easier having one to swap out than replacing while on the engine. Thanks for your help!

[Viper]

Pretty sure it's 47-59362T1 for the impeller only. That number may have been superseded now. I can check and let you know. There is also a Sierra part number if you're okay with non OEM. When you say "kit" what is it that you're looking for because there are several kits with different hardware included.

Don't forget that the oil in that pump assembly needs to be replaced periodically. Make it part of your regular maintenance by replacing it every time you replace the impeller.

[tonyiiiafl]

I am looking for the impeller and wear plate, o rings.
EVERY year I remove the fuel pump and replace the gear lube in the boss part of the pump. I had a failure on one and saw it was all washed out and like water. So now it is part of the preseason maintenance. EVERYONE should heed your advice on this!

I believe I have pump 46-807151A8. Would I be looking for kit 46-807151A14?

[Viper]

Pretty sure that part number includes the pump housing. Is that the kit you're looking for?

[Viper]

In any case, you're basically looking for a Bravo pump impeller, for the older style pump with the D shaped shaft.

Check the wear plate, if it's grooved get a new one or you can flip those over. Also check the bottom of the inside of the pump housing, that will indicate if you need a new housing or not.

[tonyiiiafl]

I guess I should have said the pump I have is BRAND new, just been in the box for 2 years. I would be getting the impeller and O rings, the plate and housing is new never used. I just am leery of putting the pump in with a 2 year old impeller that probably has a "set" in it.

[Viper]

Ya I caught that, that's why the part number for the impeller only. Just putting the other info out there for the benefit of others. Good move on replacing the impeller on a new pump by the way, no telling how long it was on Merc's warehouse shelf or the retailer's. If the pump was rotated periodically while on the shelf there wouldn't be a problem, but you know that didn't happen!

[mjk1040]

I understand your concern that the impeller has been inert for a few years, but if it wasn't exposed to any elements shouldn't be like brand new? Or you feel age has a effect on the rubber?

[bud37]

Source of the post I just am leery of putting the pump in with a 2 year old impeller that probably has a "set" in it.

I agree, what I have done was take the new impeller out to be on the safe side and replace with a new one then keep that one as a spare, you can tell if it will be ok later if the "set" straightens itself out.

[mjk1040]

Ah good idea! That would most likely tell you if it was still flexible thus most likely still good.