I have a 06 450 and have four NO-toil filters two of which I have had longer than the other two. My question is? the two older airfilters have started coming loose at the top of the seam(where the filter is seamed together) but it is not tore through(just the seam has come apart) Can I still use them or is there a chance that dirt could get through(should I buy two more?).............Now on the chain!..... My sprockets still look pretty good the front one may have a little turn to it and the back also(not much though) So should I get another chain or just wait and get one when it is time to replace the sprockets. I put this chain on when I put the sprockets on and it is a renthal works chain and the sprockets are renthal. I heard that if you replace the chain every so often the sprockets will last longer........I also heard that when the chain gets flat spots in it on the top of the links it is time for another one. Mine has these flat spots so should I just replace the chain and not the sprockets.