1977 Mercury outboard motor

[joe tiu]

I have 2 problems,
1. When starting I feel like the motor is not getting fuel, I have to hand pump then it will run.
2. When running at 4500rpm, it will drop to 3500rpm, it will continue to do that.
3. What is the fuel mixture for this motor, 32:1, 40:1 or 50:1

Thank you for your help.
Joe

 

[Flying Scott]

I run 50 to 1 oil at that ratio in my 1977 50 hp 1962 Merc 60 (6 hp) without any problems. Make sure it is an outboard oil made to do that. You should do just fine. Alan

 

[Chris1956]

Joe, If she will not maintain RPM at speed, pump the primer bulb, and see if that helps. If it helps, rebuild the motor's fuel pump. If not post back with symptoms.