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Idle mixture settingIbm not getting something

dhyams

Regular Contributor
"[I'm just trying to make

"[I'm just trying to make sure that the directions aren't flawed, because they don't seem to add up]

From the Mercruiser service manual:

[mercruiser] 4. With boat in open water, place remote control in forward gear, idle position.

[me] OK, I can do that.

[mercruiser]5. Disconnect throttle cable barrel from anchor stud. Be sure not to lose spacer on anchor stud.

[me] OK, so we are coasting around with my wife at the wheel, and I'm sure I'll scare her by possibly causing the boat to accelerate without her input. But OK.

[mercruiser]6. Adjust idle speed adjustment screw to obtain
550-600 RPM, in neutral gear.

[me] Huh? I thought we were in forward? Is this instruction out of place, and I should have done this already? If not, then I guess I have my wife shift back to neutral? What was the point of shifting to forward in the first place?

[mercruiser]7. With engine running at specified RPM, adjust idle mixture needle as follows:

[me]RPM? What specified RPM? Are you talking about the idle RPM written on my splash guard?

[mercruiser]a. Turn idle mixture needle in (clockwise) until
the engine speed begins to drop due to lean
mixture.
b. Turn idle mixture screw out (counterclockwise)
until the speed begins to drop due to
rich mixture.
c. Turn screw in to a point between these two
extremes to obtain maximum engine smoothness
and RPM.

[me] Am I supposed to still be in neutral? I guess so....

[mercruiser]d. Readjust idle speed adjustment screw until engine idles at 650-700 RPM in forward gear.

[me] OK, so shift into forward and adjust. What exactly was the purpose of disconnecting the throttle again?"
 
Sounds like three adjustments

Sounds like three adjustments at once..my guess
A) in neutral adjust idle mixture to get smoothest idle (mixture screws on carb)
B) in neutral set idle stop screw on throttle to desired rpm 600ish
C) in forward gear adjust throttle cable linkage barrel screw to ensure idle rpm stays near neutral idle setting when in gear..ie: throttle cable does not increase rpm till the unit is already in gear.
Clear as mud?? Hope this helps.
 
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