350 mpi water pump ?

Hello to all...

i am located in Georgia and due to various reasons, I haven't been able to take the boat out, it's a 2009? Chaparral with the 350mag engine and bravo 3 drive. I believe the water pump is bad, I put it in water today and could not get water to circulate, checked for obvious obstructions, assume a pump problem? Looks like a fairly straightforward replacement procedure? Boat has 110 hours....
thanks for any help

When you say water pump..... are you speaking of the "seawater" pump?

You posted in the Marine Power Engine Forum, yet you mention Bravo III drive.

Merc uses a belt driven seawater pump for their B drives. These are typically a PITA to access the pump for impeller maintenance, and maintenance is often defered because of this.

Father Time takes it's tole on impellers more so than actual usage in terms of engine run time.
A brand new impeller can go bad simply from being left in the pump housing too long and with no operation.
This is due to the impeller material taking what's refered to as a "set".
The vanes simply loose resiliency from being held and folded against the eccentric side of the housing.
Once the resiliency is lost, these will not function well.

So... regardless of your rather low 110 hours, you'll want to at least remove the impeller and inspect it.
Since these impellers are relatively inexpensive, you may as well replace it.
While in there.... examine the pump body for excessive wear.

Better yet..... if you have the space in front of the engine, retro-fit a Johnson crankshaft pump in lieu of the Merc belt driven pump.
The Johnson pump lends itself no belt tension side load on the shaft bearings, and easy impeller access.
4 screws removed, and the impeller is right there in front of us.

From what I understand, a complete new Merc pump runs into the $500+ range.
The Johnson pump can be had for around $180, and will include a new impeller.

You'll spend several hours doing the conversion... but this is one-time ordeal.

If interested, this topic has been discussed here a few times.

.

Yes I'll search for that thread...I wasn't sure where to post, I started to post in bravo III forum, but talked myself into thinking that was only for tranny, this was for the engine. My bad.

I like the idea of a crankshaft driven pump.....

Somedevildawg said:

I like the idea of a crankshaft driven pump.....

Click to expand...

Yes... I do also.
Some think this to be a Volvo Penta thing only. Indmar, PCM, Marine Power, Crusader, Volvo Penta, and many more use the crankshaft seawater pumps.


Here's the thread that was started in the Crusader forum section.
You'll see links to the other threads in this one.

Meanwhile..... this will be similar to what you'd end up with.