115hp 1977 Mercury loses power

[headcopter]

Hello, I have recently had a 115hp 1977 merc fitted to my 17' F/G runabout. The motor has plenty of kick and runs well most of the time. However, occasionally, it loses power. I have discovered that a squeeze or two on the gas priming bulb (as it is losing power)fixes the problem and away she goes. Any ideas on what is wrong?<br /><br />Thanks. ERIN

 

[12Footer]

Re: 115hp 1977 Mercury loses power

This is fuel starvation, and anything between the tank vent and the reeds can cause it,Erin.<br />I know it's a lot to look at,but really, it's hard to find sometimes.<br />The biggest percentage of causes are,air leaks in the fuel line, tank vent clogged or shut,fuel pump, and garbage in the carbs.<br />On multi carb engines such as yours, it is even tougher to find,but find it, you must. Becuse one carb will run the engine, while the other runs dry, it will cause 3 cylinders to operate without proper lubrication.Your 115 will die an early death.<br />I hope you find it before that happens.

 

[Grant Ingle]

Re: 115hp 1977 Mercury loses power

Erin,<br /><br /> The old "Tower of Power" is usually a pretty good motor. It sounds like you have a relatively minor problem, probably a fuel pump or fuel line. Keep in mind that the motor you have is notorious for reed/labrynth seal problems. Those can be expensive.