To meet stringent EPA requirements, when shipped to our country from Japan, the Savages carb was set on the lean side. Here is what you do to rich it up a bit. Remove the top of the cab and pull the slide out. You will find a plastic washer on the needle...throw it in the garbage. This raises the needle slightly letting in more gas. You can also remove the brass insert on the rightside of the carb that hides the air/gas mixture. Tweak this a bit. I have two Savages and did this to both and they no longer backfire.

SLOPOKE MY BIKE BACKFIRES USALLY WHEN THE JOINT BETWEEN THE MUFFLER AND THE HEADER PIPE COMES LOSE. SO I PULL IT APART PUT A LITTLE GASKET CEMENT AROUND IT AND RETIGHTEN IT AND BOB,S YOUR UNCLE. ALLSO CHECK THE HEADER GASKET FOR TIGHTNES. I ALL SO HAVE A AFTER MARKET MUFFLER WHICH HAS A SEEM AROUND THE THE END OF THE CAN. AS IT IS POP RIVERTED AND THIS ALL SO SUCK,S AIR WHEN CHANGING GEARS OR BACKING OFF. SO I PUT A LITTLE CLEAR CEMENT IN THE SEEM. WORKS FINE , AL DOWN UNDER