Idle mixture screw on a 91 50HP force

[shindig888]

I know tuning an engine can vary widely but I will ask this: Is 3/4 turn out too lean? Why I ask is that I am loading up and fouling plugs like mad. Will I ever get a tan colored plug?.. "Key" possible cause: trolling near idle... Any comments are appreciated

 

[eurolarva]

Re: Idle mixture screw on a 91 50HP force

Ideling will create fouling no mater what. I would not want to go any leaner on the carb then 3/4 turn. A test for proper mixture is when motor is warmed up start at throttle and gun motor. Does it go right away or does it stutter then go or does it die. Die is too lean, stutter then goes is too rich. Takes off right away is just right.<br /><br />If under normal running conditions with no trolling you are fouling plugs I would decarb first. Seafoam deep creep works well or go to FAQ forum here at iboats. Other problems could be weak spark or fuel recirculation system is not working properly due to plugged screens. Just remember it is best to run this motor slightly rich instead of slightly lean.

 

[shindig888]

Re: Idle mixture screw on a 91 50HP force

Thanx Eurolarva. Have you ever heard of spraying a bit of water into a warmed up engine while running,to decarb it?

 

[bnk999]

Re: Idle mixture screw on a 91 50HP force

My plugs have never been tan colored -- always black with a slight residue--

 

[roscoe]

Re: Idle mixture screw on a 91 50HP force

You won't get a tan colored plug on a 2 stroke.<br />And if you do, you are running way too lean and will soon be buying a new motor.

 

[shindig888]

Re: Idle mixture screw on a 91 50HP force

I turned the screw back to 1 turn out. thanks guys. Still having rough running with new plugs