Ihave a 1982 mercury inline-6-115hp am having carb-boat motor

Check air flow meter.

Sounds like the gas isn't flowing freely into the carb. Check to see if the gas lines are open, no obstructions. Also check the gas tank, I there is a screen on the gas inlet tube and that might be plugged.

Look at an open spark plug wire. on the cylinder that made no difference when you took it off.

Yes, when you raise the motor, gas will leak from the carb bowls.

When you run a motor on muffs there is no back pressure at the prop. try up the revs to ar900 rpm's
Good luck..........

1 and 3 obviously running off different carbs,sounds like problem in distributor,have you checked spark when cold

where is fuel leaking from ? give me past history how it came to not starting ! carb clean ? sparking at the plugs ? compressions ok ?

SOUNDS LIKE THE CARB LOW SPEED JETS ARE CLOGGED , THANKS TO THIS PITIFUL GAS WE GET TODAY ,I USE A ADDITIVE CALLED SEA FOAM IT WORKS GREAT JUST ADD TO FUEL EVEN WORKS FOR WINTER SET UP TOO

HOPE THIS HELPS

Carburetors are tricky, They have to be completely dismantled, soaked in carb cleaner, make sure all the gunk is off, every jet clean and clear, If you can't get a wire through it, you won't get gas through it, make sure you can blow through it, Get some guitar strings, .009 is about the smallest guitar string you will find, you can buy them separately at the music store if you don't have one. Change the filter in the line, when the carbs go back on, the adj all have to be the same, not one wide open and 2 idleing, Float level is also important, they don't sell complete kits anymore, you have to buy the parts individually, gaskets , etc, good luck.

my uncle told me to take the spark plugs out to check if they were dry and if they were to take a spray bottle and put gas in it and spray inside the pluggs and give it full throttle. The motor started on the seconed try.