high idle in neutral

[Mike_B]

reman 1986 Merc 260, Holley 4010, Alpha 1

Finally got my boat in the water at the end of Sept. Thanks to everyone here for the help btw. I've got most of the kinks worked out but this one. When I set my idle speed in gear in the water to 700rpm @ 8? BTDC it comes out to over 1200rpm in neutral... feels like I'm killing my outdrive when I shift. What's going on here? Bad idle circuit? Idle mixture? Other than the idle issue the boat seems to run great ~55mph @ 4600rpm.

 

[thrasher]

Re: high idle in neutral

Just try seting the idle lower. You should try around 800RPM when in neutral and then see what it does when you put it in gear. If it stalls then you need to raise the idle, if it idles fine in gear then leave it as it is. My boat idles at 800RPM in Neutral and around 550RPM in gear, its a 4.3L V6.

Gary

 

[180shabah]

Re: high idle in neutral

Bring the idle down to about 650 in gear.

 

[Mike_B]

Re: high idle in neutral

I'll try backing the fast idle screw off a bit. I might order an optical tach just to be sure the dash tach is reading right. Saw one from an eBay seller for about $30 shipped.

High temps here dropped from 80s to 60s in a day so I just might get this boat good and tuned up just in time to winterize