Bravo 3 run up with water supply direct to impeller

[Shabah180]

I was recently in a bit of a "rebuttle" with a guy, he has a bravo 3, and kept burning up his impeller during run ups using muffs and garden hose. Turns out he was reving his engine and wasnt getting thenough water. He was positive, he had restricted water flow.
So, he disconnected the water supply to his impeller housing, to check flow. Out of the water using muffs he said no water was coming to his impeller. I told him muffs wont deliver enough pressure to push water up the drive and to the pump, if the drive submerged i believe the impeller sits below the water line for this reason, theres always a supply ready, at the pump.

So bottom line, ive never tried to use muffs to check flow, i really dont think it has enough to push water all the way up, and how can you be 100 percent even it it did, that the line thru the transom wasnt restricted somewhat, im guessing the best way is to pull the drive and inspect visually, or, is there a better way to make sure your getting the flow? I think b-3's pull 26gpm at idle?

Thanks again guys, just like to have the second opinion from the pro's! Lol

 

[Shabah180]

As well, if you had to do a run up onnthe bravo's and dont like muffs, could i run an 1-1/4" hose directly to pump supply to garden hose? Its kinda bypassing the drive, id think. Does anyone donthis?

 

[Scott Danforth]

Pull the drive to check for bravo-itis.

To check raw water pump output, you need the boat in water. Muffs are for firing the boat up at idle, and not all garden hoses move enough water for muffs.

 

[alldodge]

Have had Bravo's for many years and have always used a garden hose and muffs without issue. The only way the bravo would not get enough water is if the muffs are not fitting tight enough, or the garden hose water pressure is really low.

 

[Bt Doctur]

or if the rpm`s were way high

 

[tpenfield]

Had to be some sort of restriction on the inlet prior to the sea water pump. any reasonable amount of water pressure and decent muffs will give the sea water pump what it needs.

RPM is only good to about 1000 rpm with any muff setup.

 

[Shabah180]

Had to be some sort of restriction on the inlet prior to the sea water pump. any reasonable amount of water pressure and decent muffs will give the sea water pump what it needs.

RPM is only good to about 1000 rpm with any muff setup.

Perfect thanks!

 

[Shabah180]

Have had Bravo's for many years and have always used a garden hose and muffs without issue. The only way the bravo would not get enough water is if the muffs are not fitting tight enough, or the garden hose water pressure is really low.

Bit in theory, can you hook directly to the impeller housing inlet? If one wanted to?

 

[alldodge]

Bit in theory, can you hook directly to the impeller housing inlet? If one wanted to?

Yes you can hook direct to the pump. That said, the hose going into the pump 1 1/4 ID, so you would need to connect the 3/4 OD hose fitting to the larger hose fitting

 

[Shabah180]

Yes you can hook direct to the pump. That said, the hose going into the pump 1 1/4 ID, so you would need to connect the 3/4 OD hose fitting to the larger hose fitting

All dodge, what are your thoughts on some guys who submerge the drive is a cut barrel, it doesnt sit easy with me, to replicate pressure to the impeller, wouldnt the drive needs to be submerged as if the impeller housing was below waterline? So it didnt have to "work" so to speak?

 

[alldodge]

My opinion is using a barrel on a Alpha drive for a short time is doable, but not a Bravo. The Bravo needs the water level even with the drive shaft until it starts being able to draw the water in, a barrel would not be high enough.

I attached a 5/8 ID garden hose to my spare B3 drive on a stand. The hose was attached to the cheap garden hose ball valve which had about a 1/4 to 3/8 hole at both ends of the valve. The valve was attached to a set of twin hose muffs.



House water pressure was around 90 psi and I started opening the hose valve slightly, and water was leaking out the muffs but none exiting the top of the drive. Opened half way and started seeing water coming out the top, opened all the way and water was gushing out the top of drive. So if 90 psi from a 3/8 ID hole can supply water which does that, having a 1/2 to 5/8 ID hose and less pressure should be of no issue

 

[Shabah180]

My opinion is using a barrel on a Alpha drive for a short time is doable, but not a Bravo. The Bravo needs the water level even with the drive shaft until it starts being able to draw the water in, a barrel would not be high enough.

I attached a 5/8 ID garden hose to my spare B3 drive on a stand. The hose was attached to the cheap garden hose ball valve which had about a 1/4 to 3/8 hole at both ends of the valve. The valve was attached to a set of twin hose muffs.



House water pressure was around 90 psi and I started opening the hose valve slightly, and water was leaking out the muffs but none exiting the top of the drive. Opened half way and started seeing water coming out the top, opened all the way and water was gushing out the top of drive. So if 90 psi from a 3/8 ID hole can supply water which does that, having a 1/2 to 5/8 ID hose and less pressure should be of no issue

great info ad usual sir. Thanks.