1978 or 9 Mercury 70 HP (700)

[noplayn]

I'm having problems with my engine will start fine and idle fine. When I give it throttle it does fine. When I put it in gear and start giving it throttle it boggs down and dies. Any suggestions? My boat shop here said I maybe had a stator problem. Can anyone explain to me what a Stator is and does?

 

[WillyBWright]

Re: 1978 or 9 Mercury 70 HP (700)

It makes elctricity for spark. It also makes electricity for the charging system. The charging part is separate but housed in the same unit. There are High Speed and Low Speed windings for the ignition. If the high speed windings go, the motor will start and idle just fine, but begin to misfire around half throttle and act kinda like a crude rev limiter. But it won't make it die. It's below the flywheel and newer models are notorious for that part failing. The ones on yours didn't have nearly the failure rate, but most have rotted wire insulation by now.

 

[Laddies]

Re: 1978 or 9 Mercury 70 HP (700)

It sounds like the carbs are dirty or need adjustment

 

[SeaHorse]

Re: 1978 or 9 Mercury 70 HP (700)

Yup, its the carbs. Turn the idle mixture screws out about 1/2 or 3/4 turn from where they are now, then adjust from there if it idles too rough. You can't have both good idle and ability to accelerate so you have to richen up the idle in order to accelerate. Next step is redo the carbs, new gaskets, inlets and floats. Accept only the flat top floats, not the "monopoly house" style.

 

[MercFan]

Re: 1978 or 9 Mercury 70 HP (700)

****,<br /><br />I got the monopoly style black floats when I ordered from Merc a month ago :-(<br /><br />As my 2 cents...<br />If you richen the mixture by turning the screws out and your idling goes too high, bring it down again using the idling timing screw.