after just having to put in my second set of intake valves in the bike since buying it new i am searching for help. The first set of valves where after 8 months of riding so i figured i could be using the wrong fuel/filters/filter oil, to cause this. But after buying all new filters and the oil that the filter manifacturer recomends (unifilters and their super gluggy oil) and changing brands of fuel as well as adding a lead additive to my fuel, my valves are gone again. I do my oil changes at 10 hrs and valve clearences every second oil change. I do not know what to do other than go to a 2stroke (so hard to imagine) it is just getting to expensive. HELP is there anything i can do to prolong the life of my valves????????