Ok, well I'm going to go out on a limb here and say its the tire pressure in the rear tires.
.......just funnin'. It might be also be something as easy as a particle clogging the fuel line. Glad you got that one. Let me know if you are parting out that tiller or if you just want to get rid of that belt shield......seems like I could use one!!!
Cub Cadet 123