Hi!
You can mount the high speed needle both at the rear and directly to the carb . To mount it to the carb , just unscrew the big nut on the carb!

One of the best .40 sport engines on the market today.
Turns a10x6 RAM prop (British prop) at 14600rpm. Capable of turning a 12x6 prop with ease.

Runs good on 0-5% nitro. 15% nitrois just overkill!