I have a new 400 exc and went out today. Great day, but.... A little gas leaked aout the top and dripped down the tank. It left a yellow stain on the white/clear tank. Anyone know anything that will get that crap off? Also, any one ever tried ansoil? I was think about mixing the 10w40 and 20w50 in hopes it would be about 15w 45. Thoughts? Thanks.