mid 80's ford yt-16 bogs out

[big in japan]

Hi folks,
I have a mid 80's ford yt-16 that has been runing well but recently when i turn on the PTO it bogs out and dies. Any suggestions? Keeping in mind that i am a noobie to lawn tractors, but would say i'm not mechanically ignorant. I have replaced the fuel, and air filter, and plugs. I know i need new belts, but this seems sudden.

Thanks in advance.

 

[nh DRAGON]

Is there a drag on the mower? (A bunch of bailing twine or other foreign debris?) If you pull the belt for the mower and it sill does it check seat safety switch. Good luck!