Idle adjustment

[Dotong]

Hi guys,

On my mercury classic fifty, i need to adjust the idle. it was idling too high so ive been adjusting it at the control cable by moving the plastic adjuster. I adjusted it but now its too low and stalls in gear. Whats the best way to adjust this to get it right?? Although it stalls when in gear at idle it just sounds too high revs in neutral. Maybe its meant too??

Cheers

 

[Fuzzytbay]

Re: Idle adjustment

IF you post the serial number/year, it would make answering the question easier. In general Idle is set by two principals. Actual idle rpm, and idle fuel/air mixture. First set the fuel/air mixture on carbs so the motor idles at a low rpm, smoothly. Then attempt shifting into gear, if the motor stalls, bump up the idle rpms by 50 or so and try again. There may be more to setting the idle up for your motor, so please post the serial number.

 

[CharlieB]

Re: Idle adjustment

After a carb cleaning, idle mixture is initially set to one & one half turn out from lightly seated. This should give enough fuel to get the motor started and in gear in the water. There idle mixture is perfected to BEST idle speed while in Forward gear, PLUS almost 1/8 turn out to provide the additional fuel for acceleration.

Test acceleration by rapidly open the control to WOT in Forward from an idle. ANY lean cough, bog, or hesitation, then further richen the idle (turn out) just the blade width of the screwdriver slot on the idle mixture screws.

Retest and readjust to perfection.

Now you can set idle RPM using the low speed timing set screw. While in Forward gear advance/retard initial timing to obtain 800 to 850 RPM while in Forward gear. Forget about Neutral idle speed, it should be just under 1000 once set in this manner.

Added note:
You may have to readjust the throttle cable trunion to allow the throttle arm/timing lever to retard timing to idle.