need a little info for my 97 xlt600 sks. hose out of the coolant tank that runs to nipple fitting under the rad. cap with the lever has a small amount of air in the line(about 1/2" long). parked sled on a slope lifted lever on cap, started motor about 1000 rpm and could see bubbles moving through line. closed lever when didn't see bubbles after about 2 minutes. went riding for about 10 minutes and noticed small air pocket as before. did i get all the air out or do i have a head gasket leak? sled runs fine and doesn't seem to overheat. all heat exchangers are warm evenly. i don't lose any coolant out of the coolant tank. coolant rises from the low mark to high mark when starting out to when riding for about 15-20 min. i think the motor runs hotter than my other sled which is a 97 xc600. any help would be appreciated. Thanks DTH