new at this need help plz
i just recently bought a Losi XXNT off of e-bay and took it to the local rc hobby shop and found out that i need to repair my diff because whoever put it together completely stripped the threads on the nut umm i'm having issues on getting it tight enough and how to do it i kinda got the hang of it but not really also when i go to prime it the fuel just pours out of the exhaust pipe though it still primes i don't get that either i just need some helpful tips or guides plz and thank you