I just was given a Bolen 15.5 OHV and it ran fine cutting a part of the yard, and then all of a sudden it stopped moving forward. I pushed in the brake and it went about 1ft, and stopped moving again. The engine didn't stop or anything, just the drive.

Any suggestions?

Hi,
Most likely the drive belt, but could be an idler. Model number always helps.
Peace,
Clarke

Thanks Crigby, I'll check what you've suggested. The previous owner didn't protect it from weather all the time, so today before reading you message I just used lithium grease to lube up the pulleys.
Tomorrow I will check out the drive belt and idler.

The model number is #OEM-190-180.