Cole.....

If you are hitting 300 degrees with Those needle settings, you Probably have an Air Leak someplace.

Likely Places for air leaks are Exhaust Manifold, base of carburetor, Back Plate of engine, Cracked Fuel Tank or Bad O ring seal on cap of gas tank, and bad fuel lines.

And make sure the 4 screws that secure the engine Cooling Head are tight......

A small leak at any or all of those places will cause Temps to Skyrocket beyond what is safe for your engine.

Here is a link to a Sealant that is made for RC's and is immune to the Nitro based fuel that we use...
http://www.amainhobbies.com/product_...ducts_id/17237