walk behind weed wacker

[rubyjohnson]

i have a Craftmen walk behind weed wacker. It has a 6,7 briggs and Stration engine, I have had it for 16 years with no problems until today. I used it yesterday it worked fine, today it doesnt have enough power to turn the head fast enough to cut weeds, any suggestions as to what my

 

[StarTech]

Question is the engine running at full speed or has it slowed down?