with nitro engines, the needle needs to be reset, a lot. The temp, is the air dry or wet, different loads on the engine. You can set your needle in the morning and by mid day you will need to reset it.
Sounds like your running too rich. For good information on setting the needle go to www.cajungatorairboats.com in the forum under tips, there is a post carb 101. This post should help you to get your engine set right and help you to know when to reset it.