i replaced the spark plug , replenish the oil and its idle up and down then will choke out.

craftsman 6.75 mulching mower model #917378490 Briggs and stratton engine

Bev, June 2007

you'll need to adjust your fuel mixture screw. It's usually a flat headed scew that's not part of the carb where the throttle is attached too. It's a stand alone scew. With your motor at half throttle, turn this scew until the motor runs smooth and then see if the idle is working better. otherwise turn the idle srew up a few to compensate

David, July 2007