Alpha 1 Gen one new impeller won't pump

[marvinjansen]

I have replaced several impellers successfully but this one won't pump on muffs. It seemed to at first but quit. I pulled it apart and found one vane bent the wrong way and swapped impeller and housing. Made sure it is on the key. Back flushed from the hose on my 165hp inline 6 and water flows out the foot like I would expect it to. But when I put on the muffs no water came out the open hose at the engine. It is an Alpha on an older 1973 Aristocraft 19. Any suggestions?

 

[thumpar]

Re: Alpha 1 Gen one new impeller won't pump

How was the old impeller? Any chance a piece of the old one broke out and is floating around in the lines?

 

[marvinjansen]

Re: Alpha 1 Gen one new impeller won't pump

It was a new impeller. The old one I removed was all there. It flushes back from the engine hose. Maybe I need to check the thermostat, something may have clogged it there. this is the first Alpha 1 conversion to M1, but they seem the same.

 

[marvinjansen]

Re: Alpha 1 Gen one new impeller won't pump

I did have a 5hp Honda that the impeller fell apart and after replacement did clog it up and cause it to overheat and stop, was glad I had sails on that day. don't think this is the problem on this Alpha 1. Will check T stat in engine, easy check. When and if I pull lower again will put hose on inlet pipe to upper and see if water goes to engine thru that. Will also take pump apart again.

 

[ktbarrentine]

Re: Alpha 1 Gen one new impeller won't pump

I have replaced several impellers successfully but this one won't pump on muffs. It seemed to at first but quit. I pulled it apart and found one vane bent the wrong way and swapped impeller and housing. Made sure it is on the key. Back flushed from the hose on my 165hp inline 6 and water flows out the foot like I would expect it to. But when I put on the muffs no water came out the open hose at the engine. It is an Alpha on an older 1973 Aristocraft 19. Any suggestions?

Ok...I'm trying to visualise this and just can't... I've actually "tried" to get a vane to go the wrong way and just couldnt do it. Turning the vert shaft CW while installing the housing, all the vanes just go in the right way.
next...I didnt think you could run water backwards through the pump and out the "foot" (I thought the vanes would stop the flow) although I havent tried it. i do know that when I put on the muffs, no (or very little) water flows until I start the engine, as evidenced by what is coming out around the muffs before the engine starts. Correct me if I dont see the big flick... thanks!.
I'm thinking maybe a problem with the way the pump bottom plate is installed, maybe?

 

[marvinjansen]

Re: Alpha 1 Gen one new impeller won't pump

Thanks for the advice. I am about to pull it again and you may be right about the bottom plate (but the shiny side goes up) or maybe the gasket, I changed them and swapped some to use the best of 3 lower units I have. Will let u know what I find.

 

[Oshkosh1]

Re: Alpha 1 Gen one new impeller won't pump

I think that even if the vanes are turned the wrong way at installation, that they will "flip" themselves under power.

 

[Bt Doctur]

Re: Alpha 1 Gen one new impeller won't pump

water should not freely pass thru the impeller backflushing. either you missed the copper coupling tube or the hose popped off the barb end.

 

[Failproof]

Re: Alpha 1 Gen one new impeller won't pump

If the muffs are hooked to water under pressure, and the impeller is spinning the correct direction, water will flow into the pump under pressure, and help push the water through the leg into the engine. Heck, you could put a leg with NO IMPELLER AT ALL, just the complete pump housing, and the pressurized water will pass through the leg. I think something is wrong, if you can not get any flow at all

 

[marvinjansen]

Re: Alpha 1 Gen one new impeller won't pump

Good news! Decided to try it today and fired it up on muffs and water was pouring out the drain plug on the boat. Checked and water coming out of hose to engine. Hooked it up and water coming out exhaust and ports. sold boat today to a nice German student whose Dad works for Mercedes. I am sure they will do some work together on the old Aristocraft.

 

[marvinjansen]

Re: Alpha 1 Gen one new impeller won't pump

After selling I went on a ride with the buyer and his Dad and all went well. This is the best drive I have had on the boat yet. I like the way this Alpha One Gen 1 lower shifts, much crisper than my old one. The upper is quiet now and sealed up with new double face seals. I miss it already.