how necessary are valve adjustments on the vs 800 engine and do the valves tend to loosen over time or tighten up.? these engines are bullit proof i have heard. suzuki would get a bad rep if all their engines started burning valves,so i am sure they set the valves so they wont tighten up and burn them,just a guess but it sounds logical and practical for them to do that, knowing everyone will not do the adjustments because of the cost and aggravation of dropping the engine out to do it,and certainly not at 8000 miles.