1982 Mercury 50 HP idle issues

[hbertz]

Boat wouldn't start so i had the carbs rebuilt. Was able to start but would not staying running even at full throttle. Changed fuel tank and fuel lines. Now will start and stay running at full throttle but will not idle for longer than 15 seconds. There is no fuel pump but my gut still feels the engine is fuel starved at idle. not sure what to check next. don't want to replace carbs until i have exhausted all other options.

 

[oldgradywhite]

Re: 1982 Mercury 50 HP idle issues

every motor has a fuel pump and it sounds like yours is trashed.

 

[verado7]

Re: 1982 Mercury 50 HP idle issues

you had the carbs rebuilt - by you or someone else ? were the floats set correctly ? before you go into fuel pump - adjust the idle mixture screws .

start by getting it to idle about 1100 rpm on the muffs - then on 1 carb at a time - turn the mix screw to the right until it starts to idle down - then left until rpm rises and just when it starts to fall leave it there - test on the water - if you got it right - it will start very easy and have good power on the hole shot .


*** when turning the idle screws both carbs should cause the motor to idle from low to hi to low again - but the final adjustment is when turning the screw left ( richer )

*** readjust idle to about 1000 rpm in the water or 1100 on muffs - best rpm at idle in the water and in gear should be about 900 for these 50 hp motors despite what the manuakl says.

do this before the fuel pump and you need to have a tachometer installed in the boat ( very valuable tool for choosing the right prop also )

 

[hbertz]

Re: 1982 Mercury 50 HP idle issues

I did have the Carbs rebuilt by someone else. I had wondered as well if the floats were set right. I will go through the idle screw settings myself. but i swear up and down there is no fuel pump on this motor. the fuel line runs from tank -> primer bulb -> to a line tee -> to upper and lower carbs. i have been looking for a manual that verifies the setup but have been unable to.

will update on how it goes with the adjustments.

 

[hbertz]

Re: 1982 Mercury 50 HP idle issues

found a diagram for these carbs and the fuel pump is attached to each carbs. only 9 bucks to replace each one. going to try that.

 

[hbertz]

Re: 1982 Mercury 50 HP idle issues

bought the kit for the fuel pump and that worked. followed your directions on adjusting the idle in the water (which was very painful without a tach). boat runnning very nice now. will definitely put a tach on this winter. thanks for your help.