bigmike253

I'm trying to find a impeller kit for my sea water pump and all I'm finding is kits for the alpha drive. Do they use the same kits? I went to west marine and they were much help. The Merc manual did help much either because I couldn't tell exactly which kit I needed. Any part numbers for Merc or Sierra would be helpful.

The engines are 1985-1986 Mercruiser 300 Tempest 5.7L w/ Alpha 1 drives.

axapowell

If my memory serves me right, isn't the impeller on the vertical shaft on the drive? You don't have a seawater pump on the motor do you?

Dave

axapowell

If so, part number 46-96148 (A8, B8, Q8, or T8) for the last two. Any of those should work if the pump is on the lower, which it should be.

Dave

bigmike253

Yes there is a sea water pump that is belt driven. It is down low and connects directly from my thru hull fittings, to the sea strainers, then to the cooling tube on top of the engine.

axapowell

Ok, different set up for an Alpha. Is your fuel pump intrigrated on the same housing? A picture would help.

Dave

bigmike253

Sea pump is below fuel pump which is located on the block. I'll what I can do to get a picture up. West marine sold me a sierra kit with number # 18-3217D on the package it states that it replaces part # Merc 46-96148a5.

axapowell

The part they sold you is for the lower unit on your drive. Maybe you are running 2 pumps? I am not familiar with this set up.

I think you should post this over on the general tech question section. I don't think I am helping much.

Sorry,
Dave

sprink58

Wow...sounds like a Bravo set up. I've never seen that set up for an Alpha.

ThirdBird

Found an exploded view in the link below. Appears to be identical to the pully-driven Bravo setup.

http://www.marinepartsplus.com/catal...14#612268_jump

axapowell

Atta boy bird. Good find! I'm sure that is the right one. What about the internal pump? Do you still need that one too?

Dave