Help with 1250
 

I have a 1250 (i believe from 1975) that I inherited from my godfather. Since 2005 it has worked flawlessly until this year when it has started to give me some issues. It seems that when I'm mowing grass after about 5-10 minutes the tractor begins to dog down almost to a stall while making a chattering noise toward the front of the tractor, as if i were trying to mow through extremely tall grass. If I turn the PTO switch off it will rev back up to normal and straighten itself out. Then turning the PTO back on it will dog the engine down again leading to the chattering and so on. I have tried several things throughout the summer trying to diagnose the problem myself, new air filter, cleaned the carb, etc but I am pretty sure it has something to do with the PTO since turning it off alleviates the problem. My other guess is possibly the governor. If anyone on here has experienced this issue or anything like it or has any knowledge to pass on it would be greatly appreciated. I really enjoy the tractor and would like to continue using it for years to come.

Thanks,
Greg

Ummmm......

Try taking the drive belt to the deck off. Then start it, turn the PTO on. See how it acts then. Sounds like the bearings are out in the PTO.

I'd also take a look at the deck and mule drive. Maybe something is starting to lock up.