problem:
running at low speed, less than 10 mph, after about 5 minutes of running the engine sputters and goes dead; smell of gas, wait 3 minutes and it starts back up. runs great at faster speeds or higher rpms (helped to run it in low gear when going slow).

is this a float problem?
or to much heat getting to the fuel causing a vapor lock?

any suggestions on how to fix?

can a dirty air filter cause this?

 

Probable needle and seat wear especially if you smell gas(could be leaking into overflow tube behind clutch backing plate) Check oil also if smells like gas contaminated or looks overfull. Good luck