A leak in your exhaust can / will cause backfires. Any unburned fuel getting in the system from a rich intake mixed with oxygen from the leak and you get a nice big bang. Replace the gaskets at the head pipe and joints and re-torque the fasteners and you should have a pretty easy fix.
'04 Nicky Hayden
Flapper/PAIR Mod-Ladybird Full Ti Moto-GP -w- Long Cans-Proton Flushmount LEDs
HotBodies Undertail-Tyga CF Hugger-HEL Lines
Custom plate mount w integrated LED brake light
15/41 gearing-PCIII USB-Speedohealer-Carbone Lorraine Pads
Spencer Seat mod-Ceramic dual coat headers
It is a wise man who knows where courage ends ...
and stupidity begins.