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: 3862
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

I have a 2001 mercury optimax 200 when running at 4800 to 5000

This answer was rated:

I have a 2001 mercury optimax 200 when running at 4800 to 5000 rpm it starts to cot out. Sometimes if I back off it will be ok other times it will die. I have replace the spark plugs and checked the coils by unhooking them one at a time and they all seem to be working. Do you know what may be causing it to cutout?
Hello, my name isXXXXX you for allowing me to assist you today.

Do you have a set of fuel pressure gauges that can read at least 100 PSI?
Customer: replied 3 years ago.
No I don't have any.
You are going to need them to test the fuel and air pressures as the engine is running.With out it we are just guessing as to what is wrong with the engine.
Customer: replied 3 years ago.
Okay I'll get some tomorrow. Thanks for the help.
Test the fuel pressure on the Stbd rail with the key on engine off. You should be getting 40PSIwhile the pumps run and hold at 20 when they turn off. Running the engine you need to be getting 90 fuel and 80 air.

Please let me know what you find. Tomorrow my sons have a football games, and I will be back online after 9PM CST. Look forward to getting you fixed and back on the water.

Charles and other Boat Specialists are ready to help you

Related Boat Questions