[Raceboy]

Originally Posted by jpnovak

The issue with cold start is more air flow. your RSR cams with narrow lobe centers and high overlap exasperate the inefficient combustion issues that cause low airflow. You can enrich the mixture on cold start - but this just keeps it running. It does not increase the idle speed. You can increase the ignition advance (to a point) and this will add some rpm but not enough to get you to a high enough rpm.

Low rpm cold start needs more airflow. This is done by your right foot, hand throttle or some external idle valve.

There are different ways to accomplish the last two on the list above.

One of the reasons I went for electronically operated throttle with ITB's: no need for external idle valve which would be a must if wanting to retain nice behaviour in all conditions (cold starts, high beams, fan, A/C etc).