I just bought a 2002 XR650L with 5400 miles on it. cosmetically it is in pretty bad shape but i thought with only 5400 miles it would be a good buy. i rode it home about 40 miles away and it started poping really loud and finally stalled and wouldnt start again. i hear the starter turning the engine but there is not even one thump of it trying to start. i took it to the shop and they say it has no compression. how can this be? i made it all the way home going about 70 mph and it fealt fine and all of a sudden no compression? it has oil in it and it didnt feel hot or anything. i have a chance to buy a xr650R engine for about $1200, can i swap the L engine with an R engine or should i have them take the engine apart and see what exactly is wrong with it and try to fix it? thanks for any help.