This is all I could find for you, from the Michigan DMV website:
Michigan Commercial Drivers License FAQ's - DMV.ORG
Are there CDL exemptions?
Yes. You won't need a Michigan CDL if:
You're on active duty in the military―or in the National Guard―and are operating military vehicles with military licenses.
You're a police officer or firefighter and are operating emergency vehicles.
You're a farm worker operating a farm vehicle within a 150-mile radius of your farm. (You will need an "F" endorsement on your regular operator license if you're driving a combination vehicle whose towing vehicle weighs more than 26,000 pounds.)
You are driving your own motor home.
Also, this is how Michigan defines a farm tractor:
Michigan Vehicle Code Section 16 - "Farm tractor" defined:
Sec. 16.
"Farm tractor" means every motor vehicle designed and used primarily as a farm implement for drawing plows, mowing machines, and other implements of husbandry.
History: 1949, Act 300, Eff. Sept. 23, 1949
Ps. Nice toys by the way, especially the R-1! I am a sportbike nut also, well...used to be. I don't own them anymore (sold them last summer), but I can still feel that acceleration! I bet your neighbors love that D&D pipe!
Podunk