I have a 1990 Honda 3813 riding mower. It starts fine, but once I engage the blade, the mower proceeds very slowly in 5th gear then dies out (chokes out). When I don't have the blade engaged, it moves fine. It also will not go up a slight incline without choking out. Any suggestions?

Are you using fresh gas? I'd also go over the pulleys and such and make sure they move freely (just to rule it out).

Thanks for the info on the pulleys, I will check this weekend. All new Gas. Not mixed with old gas.