I have a 1980 Johnson 70 hp 3 cyl outboard motor. My question is,why is it that when I have a primer bulb with 5/16" ends the engine runs perfectly but when I replaced it with a 3/8" end primer bulb,the motor would start to bog out when at full throttle. It will work great at half throttle,but not full. I put back the smaller primer bulb and the motor works perfect.?????
