Target AFR at Idle/Cruise with carbs Options

[yeahmag]

I was reading a thread on carb tuning that John Connolly of aircooled.net was on and he suggests a much leaner idle/cruise AFR than what I've been running. I've set a target of 12.5-13.5 in that range, but he suggests you can go much leaner than that.

This may also explain why Jake thought I was nuts when I went from a 60, to a 62, and then finally a 65 idle jet on my 40 Dellorto's. Does anyone have any real world insight on this?

I've loaded in my 60's for a ride tomorrow...

-Aaron

[Ductech]

Aircooled motors like a little extra gas to cool with also. Almost like a turbo water cooled car would want. If emissions are your concern then tune to stoich, 14.7

Personal experience of somewhat unrelated nature yet related ... Aircooled Ducati's Love cruising around in the mid 13.0's

I would worry about maybe loading up plugs if you run to rich a mix at low throttle openings.

I have no exp with those carbs so I am unsure of the architecture and how complicated the cruising / low end circuit is.

oh and (IMG:style_emoticons/default/agree.gif) with the head temp sensor. This will tell you what afr the motor likes!!
Thats how the big boys tune. they watch the sensors as they make changes and compare the data! Use your calibrated butt dyno with a headtemp sensor and you could really find the smoothest / coolest running combo.

But dont start thinking about other variables like ignition timing or else you could get lost!!!