How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Tan Your Own Question
Tan, MerCruiser Certified Technician
Category: Boat
Satisfied Customers: 11071
Experience:  40 yrs. experience with complete engine repairs both inboard/outboard and MerCruiser Certified Technician.
Type Your Boat Question Here...
Tan is online now
A new question is answered every 9 seconds

I have a mercury 50 hp efi outboard. I don't have any power

Customer Question

I have a mercury 50 hp efi outboard. I don't have any power to the fuel pump. What would be the cause
Submitted: 1 month ago.
Category: Boat
Customer: replied 1 month ago.
The motor died at 20 mph . I took it to a mechanic shop and I think they are going to order a 500 dollar pump. When i think it is a fuse or something providing power to the pump. No power to half the fuse block when key is on . Don't know if this normal. Motor was running flawless until this happened. 40 hrs on the motor
Customer: replied 1 month ago.
Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call.
Customer: replied 1 month ago.
Let me know if you need more information, or send me the service offer(s) so we can proceed.
Customer: replied 1 month ago.
No phone service from 7:30 am to 3:00
Customer: replied 1 month ago.
I'm going to the mechanics shop to look at the boat. I can take your call anytime
Expert:  Tan replied 1 month ago.

Hello, I'm Tan. Welcome to JustAnswer. I'm reviewing your question and will reply momentarily.

Expert:  Tan replied 1 month ago.

Could I get engine serial number please?

Have you checked all the fuses in the fuse holder # 26 is the cover to fuse holder?

Remove cover and check all the fuses. Are they all good?

Customer: replied 1 month ago.
All fuses are good. Have power to fuel pump in first 2 seconds. No sound from pump
Customer: replied 1 month ago.
Expert:  Tan replied 1 month ago.

If the pump is getting voltage and not running the pump is bad.

Your going to have to try to apply voltage to the pump directly. Can you get some jumper wires and apply voltage directly to the pump just to be sure it is the pump.

To get access to the pump you have to remove the top of the VST then unplug the pump# ***** then apply 12 volts to the terminals you removed the terminals # 21 from.

Expert:  Tan replied 1 month ago.

The terminals circled are the terminals that connect to the pump apply voltage to these 2 terminals. Does the fuel pump run?

Customer: replied 1 month ago.
I'll have to take it apart tommorrow and do that. I did test the circuit at the pump and have 13 vots for about 2 seconds. Can I respond to you tommorrow after I do that?
Expert:  Tan replied 1 month ago.

Ok tomorrow is fine.

Thank you..Tan