Help!! Water Pump Not Working
 

I pulled the alpha I drive off of my 1985 Scarab to install a new gimbal bearing and paint the outdrive. While I I had it off I removed the lower unit to check the waterpump. It looked fine, so signs of wear at all. The guy that I bought the boat from hardly used it. Today I put the lower unit back on the upper gear case and put the drive back on the boat. I fired it up for around thirty seconds just to see if it would shift OK and to make sure that I got everything back together ok. I DID NOT have the water hose hooked up to the drive for the brief 30 or so seconds when I had the motor running and was shifting the drive. After everything cooled back down I then hooked up the water hose to the drive and fired up the motor. NO WATER COMING OUT OF THE THRU-TRANSOM EXHAUST!!! I let it run for about a minute to see if the water would work it;s way though to the exhast. NOPE, NOTHING. So I shut the motor off.

What's wrong? Why am I not getting any water to the motor? Does the motor have to get hot enough to open the thermostat before it will start to sirculate water throught the motor and out the exhaust? Did running the motor for 30 seconds without the hose hooked up melt the waterpump impeller ??? What else should I check?? Thanks for the help, hopefully I can get it going by Sunday.

The impellers don't like any more than 10-15 seconds w/o water before they go south. Never run them dry. You will always have water coming out your exhaust once the motor is filled with water. Doesn't matter if motor is hot or cold. water in=water out

Yup, the impeller is toast in seconds unless you have a blue one from Globe. Sorry.

Also check to make sure the water tube between the upper and lower is in place and that the rubber seal at both ends did not get dislodged

Thanks for the quick responce guys. So you think the inpeller is toast. Even if the impeller is damaged, wouldn't it still pump a little water through the motor? Does the friction of the rubber impeller on the metal housing just melt the rubber? Thanks again for the help.

If you had it running say 1 minute, which I suspect you did if you were shifting and stuff, you fried the impeller. In one minute the impeller would go around say 1000 times. Thats a lot of friction to aborb without water flow. I once interupted a guy running his scarab with no water running to it. I listened to it run 4 or 5 minutes before I said anything. It had thru hull exhaust and when I started talking to the guy, he couldn't hear me. He got all pissed and stomped to the helm and shut it down and yell to me WHAT!! I said you have no water running to your outdrive, thinking he just forgot it. He yelled back irritated that he was only running it ten or fifteen minutes and that it didn't need water for that short time. I said Oh, now I see. Then drove off. Next time I saw him was the next spring being towed in from about 1 mile out. Wonder what the problem was?? He's nice to me now ;) Change the impeller.

BT:cool:

Can you say "toast"?
That impeller will litterally melt in the housing.
Teart it apart, check the housing and base plate. Call (or go online to) Globe Rubber they have a replacement that'll last for 15 minutes without water.
If the housing is damaged and the baseplate scored in any way, replace them. It's better to do it now than to find out later when it doesn't work right.

Thanks for the help guys. I pulled the lower unit and checked the impeller. Man, it was toast. All of the rubber vanes were gone and all that was left was a mangled hub. It also chewed up the housing. Where do all of those rubber pieces go? I bought a new kit, installed it and it works great. Finally got the boat out for the first time this spring. I'll never fire it up without the hose hooked up again.

Im not sure where they go on an Alpha. On a Bravo 1, they go plug up the oil cooler if they make it out of the pump housing. Glad you go it fixed. I also learned the hard way many years ago.

The pieces go up into the water passages in the drive and motor.
Start looking with a flashlight and find as much as you can.
I've been told they can really screw things up.

God luck.

I ran the motor for around 20 min. on the garden hose, and then I pulled the thermostat housing and didn't find and peices up there. I did see a few small chunks that came out of the exhaust, but they were only the size of a BB. I ran the boat at the lake last sunday and it stayed as cool as can be.

imq707s,

You need to back flush the system to get the old impeller out of the coolers. On the bravo drive you remove the inlet hose at the thermostat housing and attach a garden hose. Then you remove the hose from the seawater pump and let the water flow out 5-10 min. I'm not sure which hose you would remove with the alpha. My guess is the hose coming from the drive.

Dan

What "coolers" are you talking about? I think that the only cooler that I've got to worry about is the power steering cooler. The only place I can think of where small pieces of rubber would get caught would be in the thermostat houseing. Everything else is very large diameter tubeing. I'll check on the backflushing idea. Thanks.

On an Alpha the pieces of the impeller (if they are on the big side)usually wind up trapped in the water passages in the upper housing of the drive. A little smaller and they will make it to the PS cooler. This is a big pain, but you need to follow the water flow and find all the pieces. Play detective, find the pieces and account for all of them. If they make it past the drive check the power steering cooler. The only way to really check it is to pull the water hose off the inlet side and look inside.

If they are small enough to make it past the PS cooler they are usually too small to cause any trouble. Phantom fragments may cause mystery overheating down the line. Back flushing as Dan suggested is a good idea, but unless you have a lot of volume and pressure from your garden hose don't count on it.