hunter2664
New member
Hello. I'm new to this bo
Hello. I'm new to this board I would like to introduce myself. My name is Jim OBoyle. I'm new to boating but have been an ASE certified automotive technician for 13 years. So I would like to think I have pretty good understanding of how motors work. However I am stumped by a problem I'm having with my Mercury outboard. The motor is a 1980 70 hp 3 cylinder. I purchased the motor not running.I rebuilt the powerhead due to the number one piston failing (melted piston). At the time of the rebuild I also rebuilt both carbs and replaced the reeds because they were out of spec. The water pump is new. The problem is that I decided to start the motor at home before I took it to the lake. When I started it the motor idled extremely high so I adjusted the idle down first then I discovered the bottom carb (2 Carb system)was leaking fuel from the inlet jet as well as from the center horn after a few seconds of running. I removed the carbs and reset the float levels as well as swapped the needles and seats. I still have the problem. It seems to get better somewhat if I turn in the idle screw (the manual recommends 1 1/2 turn initial setting) but I'm afraid that it might run lean. Any help on this problem would be greatly appreciated. Thank you in advance. Jim
Hello. I'm new to this board I would like to introduce myself. My name is Jim OBoyle. I'm new to boating but have been an ASE certified automotive technician for 13 years. So I would like to think I have pretty good understanding of how motors work. However I am stumped by a problem I'm having with my Mercury outboard. The motor is a 1980 70 hp 3 cylinder. I purchased the motor not running.I rebuilt the powerhead due to the number one piston failing (melted piston). At the time of the rebuild I also rebuilt both carbs and replaced the reeds because they were out of spec. The water pump is new. The problem is that I decided to start the motor at home before I took it to the lake. When I started it the motor idled extremely high so I adjusted the idle down first then I discovered the bottom carb (2 Carb system)was leaking fuel from the inlet jet as well as from the center horn after a few seconds of running. I removed the carbs and reset the float levels as well as swapped the needles and seats. I still have the problem. It seems to get better somewhat if I turn in the idle screw (the manual recommends 1 1/2 turn initial setting) but I'm afraid that it might run lean. Any help on this problem would be greatly appreciated. Thank you in advance. Jim