The stock hot start nut is made of plastic and requires a 14mm open-end wrench to remove. The hot start cable needs to be removed when removing the carb from the bike. The Zip Ty Racing Hot Start Nut makes servicing the hot start or removing the hot start from the carb easy. Here's how to replace the stock nut with the Zip Ty version.
http://crfsonly.com/howto/keihin-fcr-ca ... rt-nut.php
Please post questions or comments about this how-to in this thread.
Ken