Today I was working my tractor and while backing up from a slight downhill grade, "she" sputtered and shut off. All 3 times this occurred, she started right back up. I was running RPMs at about the same I do when operating my rear brush cutter. Any ideas...?? Started thinking some bad diesel or fuel filter? With only 65+ hours on tractor, I have yet to change it out. This is the first time this has ever happened and with it happening three in about 10 minute span I wanted to see if anyone had any suggestions or what to suspect/check? Thanks.