RE: Royal Air 40t
With that old of radio, and having it sitting for years, you need to either send it in to be checked out OR just drop some money and buy a new 4 or 6 channel system. If you plan on flying, get the 6ch. It leaves you more options down the road. I picked up a brand new Futaba 6ch with servos, batteries, switch, receiver for $100 off of Ebay. Fully programable.
Take that engine off the plane and find some of that KROIL OIL, take out the plug and spray some in the carb port, and the glow port and turn it over by hand repeatedly, both directions. Drain the oil out by tilting it whichever direction needed to do so. Spray it and do it again, over and over till the oil coming out is CLEAN.
This is some incredible stuff, like I said, my engine sat for 10yrs, I cleaned it like I mentioned, and it fired right up and ran perfect.
Good Luck, Greg