How is idle mixture set on Merc 4.3 LH?

[jtw]

I'm getting ready to do a tune up on a 4.3LH Mercruiser inboard. I plunked down the $$$ for an official Merc. service manual, but it doesn't say how to set the idle mixture. It just says "Adjust the mixture screws." <br /><br />Do you just set the idle speed in about the right place, adjust the mixture until the RPMs go to its max, then adjust the idle speed back to spec? Thanks

 

[fendersfender]

Re: How is idle mixture set on Merc 4.3 LH?

i've been taught to turn mixture screw in until motor runs rough then turn out, counting turns, until motor runs rough and then turn in 1/2 the number of turns, then reset idle

 

[fendersfender]

Re: How is idle mixture set on Merc 4.3 LH?

i've been taught to turn mixture screw in until motor runs rough then turn out, counting turns, until motor runs rough and then turn in 1/2 the number of turns, then reset idle

 

[Wingnutt]

Re: How is idle mixture set on Merc 4.3 LH?

Acutally the most accurate way is with a vacuum gage. Hook it up (but not to a ported vacuum port) and adjust for the highest vacuum reading.