Merc 496 raw water pump

[alindquist]

2006 Formula 330SS with twin Mercruiser 496 mag's, smartcraft, DTS, serial 0w618143
So I'm stumped. I bought this boat in August and it has ran great so far. I decide to do a little maintenance this weekend and now I have a problem. I pulled the raw water pump to change the impeller. Everything went pretty smooth and when I had it back together I fired the engine up and no water was coming out the exhaust, and I'm showing no water pressure on the smartcraft. I pulled it all back apart thinking that I screwed something up but everything looks correct.

I pulled the pump back off and turned on the hose and I have no water coming out the intake hose where it would attach to the pump. Shouldn't I have water dumping in to the bilge at that point? It's a bravo 3 boat, is there a shutoff valve in between the transom assembly and the pump? I'm stuck, and help would be much appreciated.
Thanks,
​Aaron

 

[Bondo]

2006 Formula 330SS with twin Mercruiser 496 mag's, smartcraft, DTS, serial 0w618143
So I'm stumped. I bought this boat in August and it has ran great so far. I decide to do a little maintenance this weekend and now I have a problem. I pulled the raw water pump to change the impeller. Everything went pretty smooth and when I had it back together I fired the engine up and no water was coming out the exhaust, and I'm showing no water pressure on the smartcraft. I pulled it all back apart thinking that I screwed something up but everything looks correct.

I pulled the pump back off and turned on the hose and I have no water coming out the intake hose where it would attach to the pump. Shouldn't I have water dumping in to the bilge at that point? It's a bravo 3 boat, is there a shutoff valve in between the transom assembly and the pump? I'm stuck, and help would be much appreciated.
Thanks,
​Aaron

Ayuh,.... Are ya usin' muffs to feed the water,..?? Are they leakin', badly,..??

Is the drive, down,..??

Yes, you should see water at the pump's pick-up point,...

Try back-flushin' it,....

 

[camalot]

The brass water pump housing is a complete disaster from Mercruisers stand point. Even the smallest grooves on the back plate and in the house with not allow the pump to prime after fitting a new impeller.
There are kits that can be purchased that use ware plates, or you can machine the back plate and buy a new front housing. I bet you have not done anything wrong at your end...........................it's just a common problem with that style pump.

 

[alldodge]

2006 Formula 330SS with twin Mercruiser 496 mag's, smartcraft, DTS, serial 0w618143
So I'm stumped. I bought this boat in August and it has ran great so far. I decide to do a little maintenance this weekend and now I have a problem. I pulled the raw water pump to change the impeller. Everything went pretty smooth and when I had it back together I fired the engine up and no water was coming out the exhaust, and I'm showing no water pressure on the smartcraft. I pulled it all back apart thinking that I screwed something up but everything looks correct.

I pulled the pump back off and turned on the hose and I have no water coming out the intake hose where it would attach to the pump. Shouldn't I have water dumping in to the bilge at that point? It's a bravo 3 boat, is there a shutoff valve in between the transom assembly and the pump? I'm stuck, and help would be much appreciated.
Thanks,
​Aaron

Guessing the boat is sitting in the water, yes you should see water come in "IF" the hose is held below the water line. Did you put the intake hose on the correct side of the pump, They will fit on either one?

 

[alindquist]

Boat sits on a lift and I'm running it on muffs (yes they leak pretty bad)... I have read about the wear plates, I'll probably going to buy the rebuild kits form JCmarine
http://www.jcmarinellc.com/water_pump_kit.htm
Just seems weird that I don't have water running into the bilge with the hose hooked up... Could just be that my muffs suck.

 

[alldodge]

Boat sits on a lift and I'm running it on muffs (yes they leak pretty bad)... I have read about the wear plates, I'll probably going to buy the rebuild kits form JCmarine
http://www.jcmarinellc.com/water_pump_kit.htm
Just seems weird that I don't have water running into the bilge with the hose hooked up... Could just be that my muffs suck.

That would be my guess, or your water pressure is really bad.

 

[tpenfield]

Possibly you hooked up the hoses backwards as it would do what you described.

 

[Bondo]

Possibly you hooked up the hoses backwards as it would do what you described.

Ayuh,.... That's my 1st thought too,.... pretty easy to do,.....

 

[alindquist]

Not hooked up backwards... I didn't touch the starboard side so I have a reference, plus I think they are dummy proof, one is smaller than the other.

 

[alindquist]

Problem solved... The housing was scored so I used the Kit from JC marine (Captain's Choice in Ft. Walton Beach had a few in stock) and everything started working again. Now that I know what I know I can do the other engine. Thanks for all the help.