JD LX 277 mower engages then stops

I have a used JD LX 277. Motor startsand runs fine after a new air filter, but now when the mower is enagaged it only mows about 5 feet then the blades shut off the mototr continues to run. I can shut the blades off with the switch and start them again to mow about 4 feet, then the blades shut off again. Frustrating since I have 5 acres to mow. Any ideas what my issue might be?



thanks!