Originally Posted by Cory B

I found the stock needle settings for the GRP .21

I called Horizon Hobby (since GRP doesn't include the settings in the manual or website) and they told me this:

HSN out 4 turns
LSN out 2 1/2 turns

This is what they said the stock settings are. I adjusted my needles to this before starting it for the 1st time and it was spot on. motor was plenty rich and idled for an hour with plenty of smoke.