[Lynn E Moyer]

Blowing snow yesterday. When load was put on engine it would bog down. Acted the same as when you move throttle from idle to wide open. Really noticed yesterday, below zero.

 

[flymo]

Check air cleaner for mouse nest or other obstruction.
Replace fuel filter.
Check fuel flow - tank pickup, fuel pump.

 

[JDF/ SwampFox]

A lot of different things could be an issue but first of all make sure the tractor is operating properly within Hi and Low idle ranges. (Full throttle and idle) You'll need a tach to check it. Then check everything else, plugs? Coils? Premium gas? and everything Tim said?