XLX,IS A LOW COMPRESSION VERSION 1983 SPORTIE WHERE XLH IS THE HIGH COMPRESSION VERSION.. There are probably other subtle differences.. they do however seem to have one thing in common..their weakness in the bottom end as Judy mentioned. which brings me to my problem..my motor has %!ยค itself and I am looking for a replacement motor.. if anyone is able to assist it would be greatly appreciated..is it possible to replace the motor with other model motors? would the bike make a good anchor?