75 hp chrysler outboard running issues

[Ceolasswell]

OK, first I just want to throw out that I am NOT familiar with boat motor lingo but I will try my best. I need help and guidance to figuring out my dilemma with my outboard. A few weeks ago the motor was running like a champ, the following week I took it to the lake and it would not start. I finally got her running but I had to 'full throttle' in neutral just to keep it idling. put it back in 'neutral' and she died. started up again on 'full throttle' and was able to get it in gear and running. she ran good but started to bog down and died. I had 3 gallons of fuel in this tank and only went about 70-80 yards when it bogged down and died. I checked the tank and it was empty. I hooked up the fresh tank with 6 gallons and got her running again, but was still running 'hard' and acting like it wanted to die. I went about 100 yards on this tank and burned 3 gallons from my fresh tank. I launched the boat and went home, waited till day light and checked my motor. I cleaned the carbs and hooked it up to the water house snorkel thing and ran it. it again would not idle properly and it appeared to have, what looked like to me, SNOT coming out of the exhaust. I tuned her off and then I noticed my lower unit was leaking lubricant. ....... .. .. my question is, has this ever happened to anyone? and if so what the heck is wrong with it? it almost appears as if the lower end lube is getting into my fuel mixture and getting shot out the exhaust... is this possible? how will I fix this problem? please help,

thank you

Russ

 

[jerryjerry05]

Excessive fuel use can be a bad fuel pump diaphragm.
Take the pump apart and see if the diaphragm has a hole or tear.

Do a compression test too.

 

[Frank Acampora]

It can be a bad fuel diaphragm OR stuck carb floats not closing the inlet needles. Checking and changing the diaphragm is the easiest so should be done first. Since no one will have records going back far enough, ask your Mercury dealer for a fuel pump diaphragm for am early force--up to 1990 or any year which did not have a Mercury fuel pump.

To check the floats, you would need to remove the carbs and then remove the fuel bowls.

 

[MickLovin]

Had the exact same problem and found it to be the pump Diaphragm, as mentioned can also be stuck or wrongly adjusted floats. Also check your plugs to make sure you have spark on all cylinders.