1976 mercury outboard 85 hp, takes 2 cycle oil mixture?

It starts up and runs fine ,but as i bring the throttle all the way back down it shuts off,it wont idle,what could be some of my problems,also i have ISO-HEET to put in the gastank,cause i thought there might be water in the tank is iso-heet alright for it,and can i put carburetor cleaner in the gas ,cause it has dual carburetors,any help would be great ,Thankyou
1976 mercury outboard 85 hp, takes 2 cycle oil mixture?
do you have a water sepperator?


if you do change it also you might want to raise the idle
1976 mercury outboard 85 hp, takes 2 cycle oil mixture?
Yes your motor MUST have oil mixed in the gas. To run without oil will burn it up! It also must have the lower unit in or have water running through it or you will burn the pump, then the motor will overheat. How old is the gas you are trying to use? Fresh fuel will also help. Depending on how long it's been sitting, the carbs probably will have to be removed and cleaned. I would not add anything to the fuel.
Reply:Be carefull to use only Hi octane fuel prefer Mobil and Merc oil at a ratio of 50/1 a dash of lead replacement Will not go astray.This will work in Australia as you can not buy leaded fuel I don,t Know what country you are in but feel the same would apply.Remember 1976 is leaded.