'Idle drop' vs 'Best idle' procedures

[jchesshyre]

I've finally obtained an inductive tachometer so I can now set my pilot mixture by the book.

The procedure in the Honda manual for a UK '98 model with #48 pilots (as mine is), is the 'idle drop procedure' which involves setting both screws to 1-5/8 turns, setting the idle speed to 1200 rpm, turning the front pilot screw in or out to obtain the highest idle speed, doing the same with the rear, snapping the throttle a few times then re-adjusting the idle speed, then turning the front pilot screw in until the idle drops by 50rpm, then turning it out by one turn from this position, resetting the idle speed again, and then doing the same with the rear screw but turning it out by 1-1/4 turns, before finally adjusting the idle speed. 

In the Honda Common Service manual this procedure is sub-titled '4-stroke, multi-carburettor, emissions control applicable models'. Further down there is also a procedure called 'best idle procedure' which is subtitled '4-stroke, all models', which involves, as with the above procedure, adjusting each pilot screw until the highest idle speed is achieved but skips the following idle drop part. 
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Am I right in thinking that the best idle procedure is better in terms of performance and is what we should be doing on the Firestorm if we're interested in optimising performance and rideability but not fussed about emissions?‎

[VTRDark]

Am I right in thinking that the best idle procedure is better in terms of performance and is what we should be doing on the Firestorm if we're interested in optimising performance and rideability but not fussed about emissions?‎

Well there is more to it than that as this is only the pilot circuit. Think of the pilot mixture as fine tuning for the pilot jet. The problem is without having the mixture set correctly is that one cannot work out correctly if your too rich or lean on the needles and/or mains. Change one area of the carbs and it has a knock on affect elsewhere. The pilot has an affect throughout but tapers off to very little on the mains. The pilot will have an affect on rideability especially at lower speeds and at tickover.

viewtopic.php?f=31&t=14214#p238567

[jchesshyre]

I know this, but I was talking just about the pilot mixture, whether for best performance it's better to use the 'best idle' or 'idle drop' procedure...or whether the distinction doesn't really make much difference in the scheme of things (which I guess is maybe what you're saying VTRDark?).

[VTRDark]

The idle drop bit comes from screwing the screw in which basically starves the carb of fuel and eventually the engine stalls if revs drop too much. Go the other way and the revs rise but they only rise to a point and then unscrewing more does nothing. The idea is to screw one way until you hear the revs drop and then go the other way (counting the turns) until the revs rise into that spot where it starts to make no difference. Now if you managed to count the turns you then set the screw midway between the two.

I would go with the idle drop as those instructions are specific to the bike and it's a V twin so behaves a bit diffrent from other bikes that would be included in the common service manual, hence in the idle drop there is a difference between front and rear cylinder when it comes to turning it out that extra 1/4 on the rear. Being able to see the revs on the tacho should greatly help with knowing how far to go before it makes no difference. I take it your meter has a setting (dwell) for two cylinders?