They are great little engines. The one I'm currently using was wore out with 8 years previous use in the yard. Given to me by a co-worker that didnt want to deal with it when it wouldnt start. All it needed was the carb pump diaphram (sp? must be the gas). I'm pretty sure I hear a con-rod knock but it still runs good so I'll just use it another season and inspect it next summer. (Summer is building season down here) Got 4 more waiting to be used. Be careful, occasionally they like to revert back to their original use and head for the weeds.
Edwin