Hello, I was recently given a JD 130 lawn tractor from the mid 80s all it needed was a battery.

With the PTO off it runs smooth, except for an occasional 2 second bogging.

If I engage the mower it will mow for a while until it hits that occasional 2 second bog, except it won't recover until I hit the clutch. As I mow for longer periods, this problem worsens until I can no longer mow. I was not trying to mow tall grass at all.

Any help would greatly be appreciated! Where can I begin, I don't know much about lawn tractors. Thanks.