Get your bow tuned and make sure it is safe to use. I don't think it is dangerous to use carbon arrows on an older bow, just make sure you have limb dampeners and a stabiliser to absorb some vibrations. The lighter carbon arrows really just improve arrow speeds. If you look at the bows out today, they are capable of higher speeds with higher draw weights. Just stick with at least 400 grain arrow/tip combo and you should be golden.