Mower Deck issue

[tristan watson 2]

I have a 1973 wheel horse 10 automatic with a 42" cut and i am having a problem where the engine is bogging when the mower deck is engaged i bought a new belt I took off the deck and greased everything I took off the carb and cleaned and tuned it back to factory and now i am out of ideas on what is wrong

[groundhog47 347]

Not familiar with that model but do have another 73 unknown.  And I know ya already checked idler pulley rotation (free). Does it have a front mule? I see y diagram in manuals prob does. If so are/do pulleys on mule rotate easily by hand, and not bind up with guard tightened? If ya have any sweet gum trees around also check for sweet gum balls (seed pods??) in pulley v grooves or under pulley, gives mine H@#$. Prob. would smell them trying to burn though. 

Edited June 29, 2017 by groundhog47

[Thisguyisnew 114]

My c-160 acted like that when it had a bad bearing in one of the mule drive's idler pulleys. If there is nothing stuck underneath in the blades I'd start with hand turning each bearing. They should each turn smooth and easy without the belt attached. If you have a similar deck to mine there is also a flat idler pulley on the deck that needs to be checked as well

Edited June 28, 2017 by Thisguyisnew