Just went through the same thing on 6.75 briggs that had been sitting for a few years. When i got it running it had surging issue's. what i did was pulled the carb off sprayed it with cleaner pulled the needle and seat out to check blew it all out with compressed air, put it back together add some techron to the tank and let it run about 20 minutes, ran fine. The next day started it again slight surge was back, so i pulled the float bowl off and there was small particules of what looked like hard water deposits or scale, anyways sprayed the carb again cleaned the main jet with plastic wire blew it all out now it runs like a charm. But after ten years its just as easy to rebuild the carb.
Edited by hemitom (07/26/09 09:36 AM)
2006 kia spectra
2006 chrysler 300 (gone to mopar heaven)
2007 hyundai sonata