RE: rc trucks sitting for years
I find the biggest problem with nitros sitting is the fuel in the engine turns to gum and locks up the works. Sometimes you can put some after run in the carb and let it sit and they will break free. I once had one so bad that it needed a full disassembly and cleaning to get it to even turn over.
My tmaxx sat for a while (over a year) and the engine was pretty tight but turned over and loosened up once it got running.
Worst thing people do is leave fuel in the tank and that just makes a complete mess of everything. Clogged fuel lines, carb, tank, locked up engine, ect ect ect. Real PITA to fix.