Low Idle means Running Lean?

[bigbluebirdy]

Am I correct in assuming that if my '86 Mercury 150 Black Max idles low and tends to stall out in neutral, that it is running lean? If so, how can I adjust it to run a little richer.<br /><br />Thanks,<br /><br />Chris

 

[bigbluebirdy]

Re: Low Idle means Running Lean?

Sorry, it's an oil injected, V6 model.<br /><br />Thanks

 

[FlyBoyMark]

Re: Low Idle means Running Lean?

Does it "pop" before it quits after warming up? If so, yes it is running lean otherwise the idle screw for setting idle speed NOT the mixture is set wrong.<br />Make sure plugs are clean and gapped properly and check at night for high tension leaks in spark wires. Also' are carbs clean?

 

[bigbluebirdy]

Re: Low Idle means Running Lean?

Definitely doesn't pop, and carbs were just rebuilt so are clean. I guess I need to adjust the idle screw. Where is it?<br /><br />Thanks for the help.<br /><br />Chris

 

[FlyBoyMark]

Re: Low Idle means Running Lean?

First, syncronize all your carbs if it is carburated. This is done different ways with different engines. Newer Merc engines you simply loosen all the linkage screws and let the butterflies close of thier own accord with the spring then retighten the linkage screws. The butterflies in the fully closed position are setup with holes in them to operate this way. The idle "speed" is adjusted by advancing the timing, there should be a screw that limits the lower part of the spark advance when the throttle is retarded. Carbs are not opened till the engine has picked up some RPM. Idle mixture needs to be set after this on EACH carb.....manual is required for this procedure because I am not familiar with your particular engine. I strongly advise you to invest in the Mercury Service Manual......

 

[bigbluebirdy]

Re: Low Idle means Running Lean?

Yup, thanks FlyBoy. Just ordered one. I appreciate the help. Had it out today and it ran better than the last time. Maybe it was just moody that day because of the humidity.<br /><br />Thanks,<br />Chris