Trying to resolve backfiring issue on 2007..cut down white spacer to half have top off carb and see two jets ,one is large and marked 230 one is small and marked 45 if one of these is not the jet that everyone is saying they have at 155 where is it have removed white spacer and put in 2 #4 washers because 1/2 did not solve problem..Dave

Thanks..have jet in hand its a 145 will try a 155 and see if things are better...Dave