75 horse Mariner throttle adjustment

[starkyb]

Took my Tracker out last weekend to run my motor and it ran very well. But I noticed on a long run at wot, the motor started running a little rough and cut off when I put it in neutral. I noticed gas dripping from under the cowling. I detached the fuel hose, started it up again and it ran smooth again. So I started thinking - maybe too much fuel is getting into the carbs causing it to flood out. What I wanted to know if it is possible to have the throttle stop screw out of adjustment so that when the shift lever is all the way down in an effort to get max speed out of the boat it is making too much fuel enter the carbs. If so if I turned that screw in a little it would adjust how much the carbs open to match the amount of spark at wot?

 

[airkidd]

I don't think you have given enough information. Is the motor carburetor or EFI? Two stroke or four? My guess is that a throttle stop screw will me no difference on the amount of fuel entering the carb. Fuel should be allowed into the carb by a needle valve attached to a float. Fuel would be drawn through the carb by the venturi effect of air passing the jet. My guess is you got debris in the needle valve or a bad float. And fuel does not match spark. You either have spark or you do not. Don't know outboard well though, just small engines.

 

[1nebel0]

Welcome to fuel problems...I rebuild all my carb motors every couple of years and replace floats depending on condition...Needle and seats will get eaten up unless they are late model product due to ethanol that destroys everything....Fuel lines get replace also due to delamination on the inside....The fuel is 90% of the running problems today...The stop screw has nothing to do with fuel delivery....

 

[Texasmark]

Agree with "airkid" on not much info on what engine. If it is a 3 cylinder loop charged engine, the linkage setup between the carbs and the spark advance is pretty precise and you need a manual (which you can get-subscribe to on this site) to walk you through the process. BTDT

Puddling fuel inside the cowl is usually either a hole in a fuel line, or loose fuel line connection, or is caused by the carburetor float not shutting off fuel into the carburetor(s) bowl(s) when the bowl is full enough to cause the carburetor(s) floats to close the inlet needle valve. The fuel will leak out carburetor('s) venturi when the engine is raised.