[Tf175]

Our 86 also has adjustable louvers.  There are three holes at the rear , both top and bottom . The louvers do not move individually , the whole assembly moves . As other Gurus are saying,  when I see the temp going above 190 on an incline , I will back off the throttle and downshift . If the Pyrometer starts going up fairly quickly , you will see the temp coming up soon after . I only have limited experience,  but I have noted the temp will come up very quickly on a hot day when pulling a long hill with a lot of throttle .