The Gp42 is not that old. All you need to know is if it is ringed or of ABC construction wich somone on this thread will tell us shortly, then the break in is quite easy. If you have instructions follow them. If in doubt about fuel, use 5 or 10 nitro and at least some castor oil then you can't go wrong. I would highly suggest you get help at first or start with an .049 that won,t amputate what it hits.