I carry enough filter skins to keep the air filter clean until the next engine oil change. Then you do a bike service that changes the engine oil and cleans the filters. Simple, keeps the messy bits all at one time. If you only on a 1 week trip then sure, but on a longer trip take enough stuff. One key here is not traveling in other dust, keep your distance.
While weighting the bike with luggage gives you the total weight if does not identify where you could save weight. For that you need the weight of individual items. Some bicycle riders weigh all the items yep every thing, tyres, tubes, nuts, bolts, chains ... they call them 'weight weenies' http://weightweenies.starbike.com/ .
Suggest you do the similar - use the kitchen scales (should have a resolution of 1 gram .. what ever that is in ozs... about the weight of one grain of rice ) They add up all the bits to get the total. More applicable to motorcycle camping are the light weigh backpackers. http://www.lightweightbackpacking101.com/
Be careful, the lighter the weigh the less stress most things can withstand. Going from cotton clothing to synthetics means lighter weight, faster drying and longer lasting so that goes against what I just said. They do cost more, and you'll find that with most lighter weigh gear.