Sierra Raw Water Pump

[hopps1945]

Hello all, just want to make sure I am getting the correct impeller for my water pump. The pump on my motor is a Sierra 18-3150. (Replaces Mercruiser 46-807151A14) I can't seem to verify what impeller goes in this. I think it is Sierra 18-3087 but I cannot find a good cross reference that verify this. Just want to make sure before I order some. When we bought the boat, the previous owner had a few extra that he gave me but they were not in their original parts bag.

Thanks,

[boatwakes]

Both of those number are correct for that engine and pump. However, I don't use the sierra impeller because it has less blades and we've encountered trouble with them priming and losing prime.

[hopps1945]

So is there a more blade impeller form this pump or do I have to upgrade the pump to get a better impeller?

Thanks!

[boatwakes]

Mercruiser/quicksilver impellers have 10 pn47-59362T1 and the best one, silicone made by Globe manufacturing (mine's been running for 5 years now) glb2001 has 8.

[hopps1945]

So the sierra one has 8 also. is the biggest difference the type of material it is made out of that makes it superior?