RPM at Idle Question

[hanleyclifford]

To confirm, you adjust the idle screw every time you start cold? I seem to recall Hanley saying he also makes adjustment a routine part of normal engine operation.

These are the only two such reports I remember and as they come from forum regulars I'm wondering if this is more commonplace than reported.

Anybody else??

Actually, it is the main jet that I adjust routinely. BTW, with the Indigo PCV system I have no problem maintaining a steady idle anywhere from 300 to 800 rpm. The lower value is only used to check TDC timing (centrifugal should be at 0). A good idle setting is 600 rpm IMO. As far as the surging is concerned, my guess would be that the carb gasket is leaking.

[ndutton]

Yeah, understood Hanley. I apparently misunderstood Dave's comment and remembered your routine. I didn't mean to suggest it was the idle mix, just that an adjustment was a normal running procedure for you.

[roadnsky]

...A good idle setting is 600 rpm IMO.

I'm gonna go with Hanley on this one...
600-650 is a sure sign of a clean fuel path.
It's a good benchmark for the fleet IMHO.

Although, I'll confess... I still set my "norm" idle at 700-750.

[sastanley]

jwilson, I am able to get a steady idle with my PCV kit too. I've had so many issues with coils and just keeping it running this past season that I can't report exact numbers, but I am idling somewhere in the 700-800 RPM range.

Since the PCV kit didn't fix the problem, you obviously have a leak somewhere else, so check all connections that don't include the kit. You gotta have an air leak somewhere. Another trick from the car days is to spray a little carb cleaner at the suspected leak areas while you have the throttle set to allow it to surge (with the little red straw so you can pinpoint) - if you get an engine surge some carb cleaner made its way in & you found the leak. I like to use Permatex on just about everything with threads going into the motor these days to seal it up...including gaskets.

BTW - I ran my engine for 45 minutes to get from the sailing club dock to the slip with no alternator, back when I was afraid the alt. was sending 15 volts into the electrical system & the coil (turns out I had other issues). A single gr24 battery ran it no problem..I probably could have motored for several hours with two batteries on board with no alternator.

[Dave Neptune]

FWI gentlemen

I have run for over 5 hours once on the way home from Catalina. My alt. belt broke ( I had a spare but the admiral and crew were in a hurry!) when I started (with weak batteries) on "both". After starting I went back to house (the weak ones 2 6v's @ 235 AH) batteries and motored all the way home, no wind and late in the day. I used the GPS, VHF and the stereo all the way home. The engine ran fine and I was around 10.5 v when I got to the slip and shut down. After shutting down the house batteries would barely turn the engine over. The ignition only draws a bit more than a small 12v light.

Dave Neptune