Water Pump

BigBoy · Post by **BigBoy** » Mon Mar 31, 2008 4:25 pm

How does on know when it's time to replace the water pump?

I got an 01 merc EFI 225. The water doesn't shoot out of the side it more like tickles at idle. On plane I get 20+ psi on the water gauge. Any ideas?

I just had the water pump propeller changer and it trickle for the mechanic, until throttled up the motor. He didn't seem to think it was an issue.

Bill kizer · Post by **Bill kizer** » Mon Mar 31, 2008 4:36 pm

I do the impeller and water pump every other year. last year I noticed a guy was not shooting out water at a WRL event. He trimed his motor up and it was fine. Check that

Riverdawg · Post by **Riverdawg** » Mon Mar 31, 2008 4:38 pm

sounds like an impeller issue. Water should be shooting out the pee hole in a constant steady stream, when ever the motor is running.

Better have it checked out A.S.A.P catching it now will save you alot of money if your motor overheats.

The shop rate to check it out is well worth it.

~Riverdawg

BigBoy · Post by **BigBoy** » Mon Mar 31, 2008 4:47 pm

if you have a mechanic change the water pump impeller does that include changing water pump?

492slayer · Post by **492slayer** » Mon Mar 31, 2008 4:53 pm

Take a piece of wire when the motor is running (In the water) and ease it into the pee hole, it should dislodge whatever is obstructing the water from exiting. Even though the manual says to chance it out at longer periods, I change mine every year. it is the heat that destroys the impellers more than the running of them.

Riverdawg · Post by **Riverdawg** » Mon Mar 31, 2008 8:23 pm

Impellers are cheap.

I would lean towards the tech will not do a water pump unless it needs to be done and is requested by the boat owner.

~Riverdawg

NoCAL · Post by **NoCAL** » Tue Apr 01, 2008 7:10 am

Greg, the impeller is the guts of the pump. The impeller fits around the shaft and when the motor rotates the spinning impeller "pumps" the water through the rest of the motor. The rest of the job is just inspecting the housing and the gaskets if they are fine, there is no need to change them out. But the impeller is just hard rubber and can take a set to it's blades after time. Once the blades have set or if they have been eroded any, it's time for a new one. Figure on about $200 with the way shop prices are now! Or you can do it yourself. Plenty of instructions on the web.

NoCAL

David Rogers · Post by **David Rogers** » Tue Apr 01, 2008 7:52 am

First take the cover off your motor, follow the pee hole hoses from where the water comes out into the lake all the way to the motor, there should be at least 3 places where the hose goes in, 2 at the top of the head where the thermostates are and one at the bottom, take these hoses off and make sure they are all clear of obstructions, most likely a pebble, if they are all clear than it is the water pump, you will need the change the impeller and impeller housing and one of the guys who posted was correct, its not running the motor that ruins them its heat from sitting in the sun, makes them hard and cracked. Its not hard to change these, take off your prop so the lower end is not so heavy, than drop the 6 or 7 nuts and be carefull to disconnect the speedometer hose, it will drop right down and you can see the water pump on the drive shaft, just unscrew the nuts and take it appart and put a new one on, its a little work but it can save you 150-200 on labor. Take your time, its like a small puzzle, if you need help go to google for spec of your lower end, the first time I did it it took a little while, now I can do it in 30 minutes, do this a min of every 2 years and more if your boat sits in 100 heat alot.

Git-R-Dun!!

Smile_n_Jax · Post by **Smile_n_Jax** » Tue Apr 01, 2008 9:42 am

Here's a quick test I got from Buck's Outboards in Sacramento.

Run the motor to normal operating temperature. Put your hand in the stream. If it's too hot to keep your hand there, it's time to change the impeller.

chf8500 · Post by **chf8500** » Tue Apr 01, 2008 9:42 am

I have a 175 efi basicly the same motor as yours, at idle very little water comes out of the pee hole, this is normal for these motors. on plane wot or in that neighborhood, 20 psi is about rite. if your water press drops down in the 10 psi range on plane definetly time to service the pump, that number is far more important than changing the impellor on any time schedule. watch your psi and service accordingly

TonyL · Post by **TonyL** » Tue Apr 01, 2008 9:58 am

Aren't the pump and impellar one/the same??

NoCAL · Post by **NoCAL** » Tue Apr 01, 2008 11:52 am

There is a pump housing that surrounds the impeller but yeah in my mind the impeller is the pump. Shouldn't ever have to change the housing unless it gets cracked.

Ally03 200xs · Post by **Ally03 200xs** » Tue Apr 01, 2008 12:01 pm

Here is a link if you want do your own water pump replacement and/or inspection:

http://www.bassboatcentral.com/sttipswp2.htm

The instructions should be pretty close to your motor.

912nitro · Post by **912nitro** » Wed Apr 02, 2008 10:50 am

Might want to get a small wire & try to clean out the pee hole. Last year mine was the same way. I had a time of getting it cleaned out. I eventually bought a high pressure nozzle that threads onto a water hose.The one with the hhole about 3/16 of an inch. I threaded it onto another spraynozzle. Then i presses the hole onto the nozzle hole against the motor & pressed the lever to back flush it.
That did it. A yellow jacket had started building a nest in it.

Stratos278 · Post by **Stratos278** » Wed Apr 02, 2008 4:56 pm

NEVER, but NEVER, dry-run your motor. As stated earlier, the impeller is hard rubber; and as such, needs water for lubrication. Running the motor without water flowing through it, even for as little as 15-30 seconds, can destroy the impeller. If you can't get the lower unit in the water, you at least need to use "rabbit-ears" with a garden hose hooked up to it.