It seems I have a blown head gasket in my 400. I tried to fire it up today with luck, but after running about a minute......white smoke came from the exhaust......I would like to know the complications of doing the repair myself and the why the gasket (if I'm right with my assumption) blew.....I have a stage 2 jet kit with K and N Filter along with a PowerCore 4 silencer.......please get back....

 

its not too bad to do if u have a manual and can read. U have to take off plastics gas tank cover under tank. u will need 8mm 10 mm and i think 12mm to pull top cover.