Nope. It wouldn't stay running long enough to get really warmed up. I'd kick it over and it would start. The throttle was really sluggish and missing some, and then it would catch on and I'd rev it a few times, then the throttle would just dis-engage and it would shut down sounding like it does when you hit the kill switch.
I got my son's xr50 out today to let him ride, and the bike wouldn't stay running w/o the choke on. Taking the choke off would basically act almost like pressing the kill switch. I'd re-start with choke, and then when revving up, the motor would just quit after about 5-10 seconds. This bike ran great the last few times he rode. Just bought it used at Christmas. Is this from a fouled spark plug? Any suggestions would be greatly appreciated.