I have an mtd yard machine 14.5 hp, under seat is model 13am667f352, on motor is 287707 type 0224-01. Runs great and all the linkage appears to be connected. Theres no difference from first to sixth, the shifter is free floating after first. Im a fairly good mechanical person but with riding mowers i have no clue. It seems that the gear should make the pulley go back further but because of all the linkage and where everything is put together it cant. Not sure if its the belt or the pulley or linkage adjustment. What are some basic things that I can look at for this issue?