alpha 1 not pumping water,even after new impeller

[LEROYDOZOIS]

i have a mid/late 80's 140hp 4 banger with an alpha 1

i got the boat started last week and saw i had no water out the back,

took the lower leg off, impeller was in 8 pieces, found them all and installed the new impeller this morning....

filled a tub full of water, started the motor, dad said he could feel suction at the pickup grid on the leg but theres no water going up the feed tube to the t-stat housing.....

unhooked the hose to the housing, started the boat, no water at all,t-stat was opened about 1/4inch...

not sure where to go with this... this is my first mercrusier.

and before the obvious question is asked, i pulled up a exploded view of the impeller housing and put it togwther right... im just kinda EXTREMELY CONFUSED lol

 

[81 Checkmate]

Re: alpha 1 not pumping water,even after new impeller

Sounds like you still have some pc's in the system......Take lower back off.....take hose off themostat and back flush with garden hose.

Id get a set a muffs instead of the bucket/tub of water also........

Good Luck!

 

[achris]

Re: alpha 1 not pumping water,even after new impeller

If you have suction, but no water coming into the engine, it sounds like you missed the water tube when you put the drive halves back together. You'll need to drain the oil and split the drive again to realign the water tube.

Chris......

 

[Lou C]

Re: alpha 1 not pumping water,even after new impeller

How high up was the water on the drive? If it was just covering the water intakes that might be part of your problem. I'd try it with muffs and a hose first, or depending on your location can you back it in at a boat ramp and lower the drive. There needs to be a certain static water pressure to force water at least up to the level of the impeller to get to prime. The impeller in the Alpha is on top of the lower unit, and if the water just covered the water intake, that's not high enough. It can't suck water with air on top of it, LOL...

On my OMC Cobra the impeller is in the upper gear housing and for them to prime, the upper unit has to be submerged.

 

[ktbarrentine]

Re: alpha 1 not pumping water,even after new impeller

And the trouble is.... if you ran any appreciable time without flow through the new impeller (like a minute or two is all it takes to destroy a good impeller), you'll need to replace it again. At least you are getting good practice at it! And by all means, use muffs and follow the guidelines for using muffs (dang it, where did I put that service bulletin???

oh yeah...here it is!

http://www.boatfix.com/merc/Bullet/99/99_09.pdf (may not be applicable to your engine, though)

 

[ktbarrentine]

Re: alpha 1 not pumping water,even after new impeller

and before the obvious question is asked, i pulled up a exploded view of the impeller housing and put it togwther right... im just kinda EXTREMELY CONFUSED lol

Exploded diagrams are great, but did you also follow the instructions in your service manual (found in the adults only sticky at the top of this forum)? Has the correct procedure, torque specs, lubricants, etc....

Here's a link:

http://forums.iboats.com/mercruiser...placing-merc-alpha-style-impeller-387864.html

 

[achris]

Re: alpha 1 not pumping water,even after new impeller

And the trouble is.... if you ran any appreciable time without flow through the new impeller (like a minute or two is all it takes to destroy a good impeller), you'll need to replace it again. At least you are getting good practice at it! And by all means, use muffs and follow the guidelines for using muffs (dang it, where did I put that service bulletin???

oh yeah...here it is!

http://www.boatfix.com/merc/Bullet/99/99_09.pdf (may not be applicable to your engine, though)

If he missed the tube, there'll be plenty of water for the impeller. The problem is it's just flowing out of the top of the pump and out through the bottom of the drive. His impeller will be fine. Exhaust shutters, exhaust bellows, etc... a different story :facepalm:

 

[LEROYDOZOIS]

Re: alpha 1 not pumping water,even after new impeller

hey guys!!!

read everyones remarks on here and took everything back apart..... turns out i had the water tube misaligned and the pump is totally........ 100%...... FINE!!!!lol

and now, because i was so quick to put back together and see if its pumping, that i put the shift shaft in ingear and its all wacky in the control :laugh:

shes off again and ill fix it in the morning.... after i read the install instructions from mercury.

 

[GaJeff]

Re: alpha 1 not pumping water,even after new impeller

X2 on the muffs and the water tube... it's not hard to miss the pipe, especially if it's your first time. I've done it. I've also seen my water tube melted from an impeller not working. A whole new kit comes with the upper body and lower base along with the plastic tube. Depending on how long it was run with no water you should check the shutters and the tube anyways for damage. Water is the only thing that keeps those plastic and rubber pieces from melting.

You should split the unit again to be sure. And to check for a blockage.

Jeff

 

[GaJeff]

Re: alpha 1 not pumping water,even after new impeller

Guess you fixed it while i was thinking of what to say!!! Lol that's what happens when you feed the dog while giving advice. It gets fixed before your done