Hi Bigedmustafa
I have the .52 RFS and did the break-in as per the manual. I now have a little over half gal of 10% nitro 20% all Castor fuel through it.
It starts right up but can't get a slow idle. The best I get is 2700 rpm. I tried a Hanger 9 plug and an HP 4stroke plug. How does yours idle? Thanks Rich