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Matthew John
Matthew John, Marine Mechanic
Category: Boat
Satisfied Customers: 30
Experience:  Marine Technician, Certified in MERCRUISER AND MERCURY OUTBOARDS (Current), EVINRUDE, SUZUKI, YAMAHA, HONDA.
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I am trying to test a fuel pump #861155-4 is there a way of

Customer Question

Hi Pearl, I am trying to test a fuel pump #861155-4 is there a way of testing this?
JA: Sometimes boat issues seem like they'll be really complicated, but end up being easy to fix. The Marine Mechanic I'm going to connect you with knows all the tricks and shortcuts. Tell me a bit more about what's going on so the Marine Mechanic can help you best.
Customer: We have changed the long block and swapped all the old parts over, checked timing, we have a new ignition coil, new distributer, new two barrel carb, the engine runs fun on the hose and under load on the trailer, when sea trialing the vessel it intermitantly bogs down when accelerating, if you leave the throttle in place it eventually catches up and then the boat take off and does not miss a beat, slow down again and try to punch it and sometimes it bogs down and others it goes no problem
JA: Is there anything else important you think the Marine Mechanic should know?
Customer: I think that's it
Submitted: 2 months ago.
Category: Boat
Expert:  Matthew John replied 2 months ago.

Hi Welcome to Just Answer, my name is Matt.

You can test fuel output pressure around 5-10 PSI and Vacuum no greater than 3 InHg.

You can do this by purchasing a fuel pressure / vacuum gauge from your local auto parts supplier and teeing it in on the side you wish to test ( Pressure or Vacuum)

Customer: replied 2 months ago.
Hi Matt, Thanks, ***** ***** tested the pump off the boat with a vacuum and pressure gauge and I am getting around these pressures, would the next step be to check the floats on the carb?
Expert:  Matthew John replied 2 months ago.

You may have a supply issue. Are you able to substitute your supply on a test run by using a portable tank and line??

Please use caution when making connections!!!

Customer: replied 2 months ago.
I have already done this and am running on a remote tank already, I removed the fuel pump to check the screen was not full of debris too
Expert:  Matthew John replied 2 months ago.

Just to confirm... These tests (Pressure and Vacuum) are to be done Dynamically (Boat underway) at speed where problem occurs.

Customer: replied 2 months ago.
No I have only tested the pump on the bench
Customer: replied 2 months ago.
I will work on this and get the pressure gauge teed into the system and see what happens
Expert:  Matthew John replied 2 months ago.

Ok. Just give me a moment and I will get you some info for you to do Dynamic tests on the fuel pump and anything else I can think of relating to your performance symptoms.

Thanks!

Customer: replied 2 months ago.
Great thanks
Expert:  Matthew John replied 2 months ago.

Hi there, I do not have enough accurate info for you to be teeing in and making lots of plumbing connections for this type of time consuming exercise for you with this model. I would really encourage you at this stage to use a portable fuel supply and connect to your fuel pump inlet to eliminate.

Expert:  Matthew John replied 2 months ago.

Hi there! Just a quick follow up call to see how you went... Feel free to hit us up at any time!

Also, please don't hesitate to let me know of any concerns you may have in the future!

Be sure to hit my Star Rating ! ! ! ! !

All the best!!!

Matt

Expert:  Matthew John replied 2 months ago.

Hi there! Just a quick follow up call to see how you went... Feel free to hit us up at any time!

Also, please don't hesitate to let me know of any concerns you may have in the future!

Be sure to hit my Star Rating ! ! ! ! !

All the best with it !!!

Matt