Impeller questions from non engine guy

[MystiikVLX]

My understanding is the impeller pumps the lake water into the engine to cool the engine parts. Is that correct?

I read people stating the impeller doesn't push water thru until you put the boat in gear. Is that correct?

If true, then is it bad to start the boat and let it idle?

thank you for any info and advice and yes, I will be that guy to ask the dumb questions. But hey, at least I will learn something today.

thank you in advance.

[oldjeep]

The impeller spins regardless of it the boat is in gear.  Sometimes the impeller might require you to bump the throttle a bit to get it primed, although most do not.

[Bozboat]

22 minutes ago, MystiikVLX said:

My understanding is the impeller pumps the lake water into the engine to cool the engine parts. Is that correct?   YES

I read people stating the impeller doesn't push water thru until you put the boat in gear. Is that correct?                   No

If true, then is it bad to start the boat and let it idle?       Not true, ok to let idle (assuming boat in the lake)

thank you for any info and advice and yes, I will be that guy to ask the dumb questions. But hey, at least I will learn something today.

thank you in advance.               There are no dumb questions left, they have already been asked by others including myself.

 

Edited October 30, 2020 by Bozboat

[REHinH20]

20 minutes ago, MystiikVLX said:

is it bad to start the boat and let it idle?

 

Yes...starting your boat out of the water leaves the impeller to spin "dry" and will cause failure pretty quickly.

You can get a "fake-a-lake" to push water into the intake if you need to start it out of water. https://www.amazon.com/Inboard-Engine-Flusher-Mastercraft-Nautique/dp/B00H93R2IO

[JMaddogT]

afternoon, this might be a silly question but can the impeller be changed while the boat is in the water??? 2011 VLX

[hunter77ah]

Yes.  Make sure you close the intake first.

Edited May 25, 2021 by hunter77ah

[JMaddogT]

2 hours ago, hunter77ah said:

Yes.  Make sure you close the intake first.

I'm relatively new to the Malibu world, how would I go about closing it? 

[Pilotguy]

It’s a ball valve. Usually has a handle on it right near the thru hull on the bottom. Turn the handle so it’s 90° to the fitting. Best way to find it is to follow it from the water pump. Make a note of the direction of rotation of the impeller, and I use soap to help put the new one on. Angled needle nose pliers help. If there’s no broken fins keep it for a spare in the boat for emergencies. 

[Pnwrider]

As stated above follow the intake to the ball valve. In the photo below it’s the green handle. 

[JMaddogT]

34 minutes ago, Pnwrider said:

As stated above follow the intake to the ball valve. In the photo below it’s the green handle. 

39 minutes ago, Pilotguy said:

It’s a ball valve. Usually has a handle on it right near the thru hull on the bottom. Turn the handle so it’s 90° to the fitting. Best way to find it is to follow it from the water pump. Make a note of the direction of rotation of the impeller, and I use soap to help put the new one on. Angled needle nose pliers help. If there’s no broken fins keep it for a spare in the boat for emergencies. 

Thanks guys, much apricated! 

 

[justgary]

If your pump is above the water line, you don't need to close the valve.  Not every boat has a valve, anyway.  Mine doesn't.