While I have this down time recovering from ACL replacement surgery, I have had a lot of time to work on the 98 YZ-400. I finally am getting to the chain and sprockets and noticed how beat up the aluminum chain guide is. Anyone tried the TM Designworks guide. I put the rub block on some time ago, and other than the noise, like it a lot. I just wonder how the nylon piece hanging down from the swing arm will hold up. Other stuff done...new swingarm/linkage bearings, greased steering stem bearings, forks serviced new seals, long sealsavers, hebo clutch, fastline brakeline with custom bracket, complete valve job, clean up ports in head, 426 con rod, 426 cylinder, 426 piston (weisco), WR transmission, new shift forks, BBR Kicker 1" shorter, rebuilt Scotts damper, SS brake pins. Hmmmm, maybe I should have kept the 520 and just had the suspension done.... it would have been cheaper.