I have a 93 lt80 it ran and started good, then my grandson and my daughter left the choke on for about 2-3 miles. after that it was real hard to start you have to use the choke every time even if it is warm cleaned the carb used compresed air and carb cleaner everything should be good in the carb. when i checked compresion it had 70 lbs we are at 6000 feet. How much should it have? Im starting to think they leaned it way out and burnt the piston

 

I don't know about it going to lean and burning the piston, but that is not enough compression to get it started or to run. We also have a 93 and we ride all the time, (every day if possible) I have had to rebuild it almost every year we've had it. I just got ours back together a month ago and now I'm at our finial bore. Next time I'll have to get a new jug and sleeve. I don't know why, but it seems they will run forever the first time, and then its about once a year from there on out.