I had overheating problems with a DLE 20 in a Top Flite Mustang. I had the added problem of a pitts muffler. I see you have the stock muffler so you shouldn't have as much heat problems. My problems was the muffler can of the pitts was right under the carb and heating up the carb causing vapor lock. Tried several things. The solution was to duct air to the upper rear of the engine compartment from the scoop under the spinner and add a small air dam in front of the lower air exit. The ducted air in the top created high pressure there and the scoop created a low pressure area and the bottom drowning air over and past the carb the pass the muffler and out. It worked. No heating problems in even 95 degree days. Here are some pictures.