Troybilt self propelled mower with B&S model 125K05 engine. Replaced air filter housing because it was warped and primer air leaked between carb and filter housing. Cleaned carb. Mower started and ran fine for about 30 mins. then shut off. Let sit for 10 to 15 mins. and started again. Shut mower down and would not restart without sitting for 10 to 15 Mins. Sometimes mower will restart over about 3 to 4 times and then back to having to sit and wait. Any ideas? Thanks in advance.