XRAY - Model racing cars

Ok... Here is my scenario... Just reached the 1 gallon mark with my Standard plug WS7iii. Byrons 25/9 fuel and RB6 plug. Outside temp was 85 and sunny, low humidity. First heat...wayyyy too rich. started out great and got really bogged down. Lean it out for second heat. Little better power, out of fuel before the 6 min are up. around 200F...too rich. Lean a hair more (only like 2 hours at a time). Main- ran like a champ. good smoke, and good power, but still lacking topend speed a little bit (which surprised me). Brought it in and temped it. ran 6 minutes and had 1/4 tank left..286F!!! Why is this engine only running when it's temped higher? OTherwise it just bogs down from both ends. And i'm making tiny adjustments! Should I add a third shim to reduce compression? Run an OS plug instead? I'm kind of at whits end... Sorry if I sound stupid...

Try a 7 plug if it's hot and dry.

Maybe also the balance between low and high needle is off. When I retune my RBs I always start with the low needle half a turn out from flush with the carb ring and the main needle also about flush with the tube it sits in.