I have had a problem with my tach in cold weather. It would make a loud whinney noise and be pinned at 3000rpm. I have tried many different types of lubes but its a ongoing issue. Solution was to unscrew the tach cable when it is cold out while blowing snow. One day my tractor just stopped while blowing snow like someone turned the key off. Checked the fuse panel 10amp fuse blown. replaced fuse turned key and same problem. possible problem was fuel was gelling making it hard on the fuel pump. put keen flow in tank and let it sit for a few hrs. it started and put it in the shop by the woodstove. next day started it up then the same problem, blown fuse again. wiring diagram, seat safety good, neutral safety switch good, fuel pump good, next on the list was insterment cluster. it turns out that the tach cable was rubbing on the back of the insterment cluster causing it to short out and blow the fuse. just a heads up for anybody that has done the same thing with their tach cable.