tecumseh 3.8 runs fine untill it warms up

i have a tecumseh 3.8hp i rescued from the free section of craigslist. i cleaned the carb and changed the oil and got it running. i had to adjust the governor because it wouldn't come off of idle unless i pushed on the governor. it seemed to run great untill i used it.

it seems kinda slugish the first 2 or 3 seconds after i start it untill i increase the throttle (probably normal?). it runs great for the first 5 minutes. after that it starts spitting and sputtering. its happend twice.

where should i start looking?

Start it again and as soon as it dies, check for spark. If you have spark, then try loosening the fuel cap. If there is no spark, the ignition coil is bad.