Coolant full and in good condition? No air trapped?
If the cooling system looks good, what kind of conditions are you riding in? Well setup hard pack and icy trails will lead to overheating quick, as well as melt hyfax. A par of ice scratchers will fix that. I frequently find myself riding on marginal conditions (plowed roads, frozen hardpack, etc) and have never overheated after adding a pair of scratchers, and my hyfax went from lasting 400 miles to 4,000 miles (2" track)
If the cooling system looks good, what kind of conditions are you riding in? Well setup hard pack and icy trails will lead to overheating quick, as well as melt hyfax. A par of ice scratchers will fix that. I frequently find myself riding on marginal conditions (plowed roads, frozen hardpack, etc) and have never overheated after adding a pair of scratchers, and my hyfax went from lasting 400 miles to 4,000 miles (2" track)