i only have 200 hours on the machine and have had the first service done, the shop that did it seemed to not quite get the carbs adjusted real good but i dealt with it. my nephew got it stuck over a big hollow, he and i both rolled it trying to get it out. i let him change the oil and filter only to find out he over filled it with oil, i took off the breather box and had a little oil in it. i thought since it started after warming up it may be the valves. any input is greatly appreciated.