1982 mercury 50hp suges at half throttle and more

[kitokamuro]

i went fishing this morning and right off the trailer my 15 ft flatbottom screamed out to my favorite fishing hole. after sitting a half hour bite not on decided to go to 2nd best spot and the motor was surging at half throttle and above. if i kept it at 3 quaters thriottle and lumbered on after about a half mile it would clear up and scream. it did this all day. any help would be appreciated, thanks

 

[dgengineer]

Re: 1982 mercury 50hp suges at half throttle and more

Start with a compression test. If all readings are within 10% you're good. Next I'd look at the fuel system. Check for air leaks, fuel pump and carburator issues. On a 82 motor, I'd check the prop for slippage too.