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 Charles Your Own Question
Charles, Marine Mechanic
Category: Boat
Satisfied Customers: 3710
Experience:  US Navy (Ret) Certified Mercury Marine Tech with over a decade of repair experience.
Type Your Boat Question Here...
Charles is online now
A new question is answered every 9 seconds

My tach on a 2000 50hp jumping around engine seems fine indication

Customer Question

My tach on a 2000 50hp jumping around engine seems fine indication not emulating engine performance
Submitted: 1 year ago.
Category: Boat
Expert:  Charles replied 1 year ago.
Hello, my name is***** will assist you.How was the battery charge at the end of the day?Do you have a multimeter to do some testing?
Customer: replied 1 year ago.
Battery charge was in limits,
Expert:  Charles replied 1 year ago.
Ok, there are two possible causes for this problem, you will need a multimeter to locate the correct part. One is the voltage regulator and the other is the tach itself. Can you get a multimeter?
Customer: replied 1 year ago.
I have one, won't be out to the boat again until Saturday, tell what to check I can do it then
Expert:  Charles replied 1 year ago.
on the regulator itself, set the meter to DCV a scale close to 20, then with the engine running, measure the voltage on the red post of the engine while at idle and at 1500 RPM, you should see it go up from that the battery is just sitting static. Then on the back f the tach, black meter lead to the black wire on the tach, red meter lead to the gray wire Meter set to ACV, a low scale as this usually runs around just a few volts. See if the meter will move at all with the motor at idle, If you get a steady peak reading on it, the tach is bad, if the reading is constantly changing to a higher and higher voltage, it is the regulator. Let me know what you find out.
Customer: replied 1 year ago.
Will do, voltage regulator under cowling?
Expert:  Charles replied 1 year ago.
Yes under the engine cowling, should be on the right side of the engine.

Related Boat Questions