Raw Water Pick Up Pump Problem

[Kevin Smith]

I think there is a problem with my Raw Water Pick Up Pump on my 454 Merc with a Bravo II, but I need your advice.

Let me see if I can explain it. Since having some major motor work done in January, the pump works well when the boat is in the water, but when it's on the rack sometimes it won't pick up water. So I shut it down quickly to avoid buring up the pump.

I had the shop check it because this has never been a problem on either 454/Bravo boat I have owned. The shop is a good one and the owner says he has the same problem with his Bravo III, so he suggests when I first start the engine on the rack to rev it up to about 1,200 rpms to get the suction started.

So here are my questions:
Has anyone ever had this problem?
If so, how did you fix it or get around this?
Does anyone use a 5 gallon bucket with the adapter I have seen the High Performance Boats use?

Any and all advice is welcome!!

Kevin
Weekend Mistress
1991 250/270 Weekender, 454 330 hp, Bravo II

 

[keokie]

Your pump is sucking air. It may just be from a poor seal at the gaskets or the pump and/or impeller being worn out. If it is difficult to get at, I would replace the entire pump to be sure you get it in one shot. Oh, and use a Jabsco impeller. They have two more vanes, are made of better material, and will last longer then Merc's.

 

[Kevin Smith]

Pump Pick Up Bravo II

Thanks for the help so far. Maybe some additional information will help me get it back to the way it should be?

The shop put the new multi vane impellar in it when it was rebuilt and still some times it doesn't pick up with the Mercury ear muffs on. If I quickly rev it up to about 1,200 RPM when first starting the boat on a work rack it starts to work most of the time, but some times it seem stuborn and I have to shut it off.

Any more ideas of what to check?

Kevin
Weekend Mistress

 

[2000SEARAY280SS]

We had the same problem on the ear muffs until we checked the suction hose clamp at the transom mount on our bravo 1 drive. My wife the "bilge monkey" got seven turns on the clamp.

After that the drive colapsed the garden hose feeding the drive.

My guess is that we were pulling air from that spot.