One of these days I will get new tires.  This is not a question about what brand of tire to get - it is about how the tire is described.   
My manual for the 87 VR calls for 120/90-18 for the front and 140/90-16 for the rear.  Currently there are 491 Elite II on the bike, and the front has MR90-18 71H.  I think the rear has a MT or MU.   
What the heck does MR or MT or MU or 71H mean?  is a MT90-16 the same as a MU90-16?  They are listed separately and have different prices.