How long should the stock crank seals last? I've put 140 hours on my '00 KDX220 and I think both seals are going. Looks like I'll be doing a total teardown this winter. Also, has anyone modified the cases on their bike so that the seals could be replaced without splitting the cases? It shouldn't be too hard to fashion a retainer plate if there is room for bolt heads behind the stator plate and also on the clutch side (haven't been in there yet). It will be a few weeks before I tear into it but I'm curious if anyone has considered a mod. like this.