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-   -   Engine Not drawing water (https://www.offshoreonly.com/forums/general-q/210737-engine-not-drawing-water.html)

qaberdeen 06-12-2009 09:56 AM

This is a brand new motor with new everything, it's seem's abit strange to me as well, but i'm going to check for blockages in the line but it should'nt because everything is brand new, i guess with water already in the line might help to prime the system i guess, but at this time i will try anything, all the hoses r run the same way that it was rigged on my 7.4l MPI, other than the fuel cool system since i've gone with the carb seup..

thanks again. the input has been great

DareDevil 06-12-2009 10:30 AM

Take both hoses off the pump,,,the back flush from pump to drive ,,,,see if water flows.
The back flush from exhaust to pump and see if water flows.
Now u already filled the engine with water ....put the hoses back on and run the engine !!!!
Of coarse u need to stick the hose on the pump wile water is running out,,,,,without press from hose ( after u turned hose off) !

Also ,,,can it be that u mistakenly reversed the hoses on the pump (in & out ) ???

qaberdeen 06-12-2009 10:42 AM

thanks Daredevil

BajaIceBreaker 06-12-2009 10:50 AM


Originally Posted by daredevil (Post 2886717)
Not agreed,,,,if u have the muffs on the drive ,,the waterhose press will get the water to the pump in less then 5 sec. so that has nothing to do with the impeller.
I agree it takes 30 + seconds to get it to fill the block ,,,,but like i said ....that cant burn up the impeller.
because u have water there already.

SO THERE IS SOMETHING ELSE GOING ON !!!!!!!!

I'm not sure how your boat is rigged... but most boats put the impeller pump as the first gadget conneced to the intake hose (unless you have sea strainers). So if you put muffs on the drive, it will take 2 seconds to get water to the impeller, but it will still take more than 30 seconds to fill the block, exhaust, external coolers and intercoolers.

So yeah, if your boat is rigged so that the water comes to the sea pump after it goes through the block.. then your f'd!!!:lolhit::evilb::eek:


I guess the question is... "Why do you think it's not getting water?" Is it because nothing is coming out of the exhuast?

blue thunder 06-12-2009 11:57 AM

They won't self prime with no water in the intake hose. You have to put it in. Hooking up the muffs and running the hose will not push water up and into the intake hose unless there is already water around the pump impeller and the engine is running. There is nothing wrong with your setup. Run it the way I said and you will be happy.

You can tell immediately if it is pumping because the water will stop spraying out around the muffs. No need to wait and see if it comes out the exhaust.

qaberdeen 06-12-2009 12:14 PM

The engine is rigged the right way, it's just not priming, but thanks again for all the insight, because the initial start up was with no water in the lines at all, so i guess it can't self prime.

Hopefully later today, i'm going to back flush to make sure that the water is flowing, then top it up with as much water in the system as possible, put the ear muffs on and let her rip..

thanks again

onesickpantera 06-12-2009 12:19 PM

I've only replaced a couple of motors but both times I fired the boat up before putting the drive on. Just shoved a hose into the intake in the gimbal. I didn't want to chance the pump not being able to "pull" the water up through the drive.

As stated backflush everything then verify your intake and output hoses are not reversed. You may be able to unhook the input hose from the gimbal and shove the garden hose inside of it to prime the pump.

FYI...both times it only took 10-15 seconds to have water exiting the exhaust.

qaberdeen 06-12-2009 12:32 PM

Just to make sure,

the hose from the gimbal goes on top of the pump, and the hose the recircutales the water through the motor is on the bottom.
?

blue thunder 06-12-2009 01:48 PM

On mine the in port on the seapump is at the bottom. But you really need to look at the arrows on the pump to determine pump rotation and looking at the arrows determine which port is in and which is out. The pump can usually be mounted different ways so you must look at the arrows for you particular application.

Panther 06-12-2009 02:12 PM

Listen to Blue thunder, he's giving some very sound advice...

I've even seen a few boats where the first time I launch it I have to pull the hose off the intake on the waterpump to relieve any airpockets before starting.


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