Water Pump Help
 

Alright guys I feel stupid for asking this but I am having trouble with my Alpha SS's water pump. I have no water coming out of the tips.

Dropped the engine back in the boat last week, wired, drive on, washed, waxed etc... Yesterday went to test fire engine in boat and time motor. Dropped the SS into my bucket and started. Usually takes 25-40 secs for water to circulate through system and out the tips. After 1 min I noticed no water and shut off. Let cool for awhile and restarted. I could feel no suction at the tear drop inlets on the SS nosecone. Pulled the water hose going thru the transom into my oil/ps cooler and very minimal water was coming out.

Checked the FSM and a 1.50 alpha 1 pump at 800rpm idle should pump 1 gal every 15 secs. That's alot of water and I had not even half that. Thought maybe it was the impeller. It was new last year and has around 70 hrs on it. Pulled the lower off and replaced the impeller today with a new one and new gaskets. Reassembled to the T per the FSM. Before anyone says the impeller is in backwards or incorrect install, I made sure of everything. This is not my first rodeo working on Alphas.

Before assembling the lower back on I checked all engine hoses and plumbed my garden hose into the copper water tube in the upper alpha case and ran water thru the system. Water came out the tips and filled the block just like normal. So there is no restriction there. I also blew compressed air thru the low water pickup holes and found no restriction there in the lower.

Reassembled and test fired and still no freaking water. It's doing the same thing as before even with a new impeller? :confused:

Anyone have any ideas? I have made no changes or mods other than today changing the impeller.

Water comes in thru the transom to my oil cooler, out from the cooler into the block and heads then into the exhaust manifolds. I am running a Rex Marine 4 hose T stat housing that when the t stat opens allows water from the block and heads to circulate. Though there is always water going to the manifolds.

Is the water level in the bucket above the impellor?

Well this is my first time using my homemade drive bucket and the nosecone area is underwater. The low water pickup teardrops are 3" underwater but the part where the impeller is located is not. Though, I would think it would still suck water if the pickup is submerged? :confused: Maybe not and that is the problem. I've always rigged up a way to use the flush muffs on the LWP for running on the trailer but made this drive bucket to make it easier.

With muffs, you have pressure forcing the water to the impellor. Y
ou are relaying it to pull water up from the bucket. Not saying it is the problem, but I'd try it with the impellor in the water.
Hopefully it didn't fry this new impellor too. They don't like dry run time at all.

I have never had luck with the bucket method even on our old 30hp Chrysler.

Thanks guys very much for the ideas. US1 Fountain you the man! Found the problem. Found out that even though the system is self priming, the drive has to be submerged to where the water pump is underwater or it will not prime. Just because the pickup is underwater does not mean it will prime.

I rigged a little bit this afternoon and got the drive deeper into my homemade bucket. Fired up and I now have water. No problems! Lets go boating!!

IMO the Alpha pump is marginal to begin with, you could convert to a crank mounted pump and a transom pickup for about $300 and have enough water to put a pressure relief valve in. Leave the Alpha pump in just let it free flow, helps to cool the drive a bit.