Wilsons Sandbox

Just a note. I posted a note a couple of months ago about having a strange noise coming from my 03 KLR engine with 40,000 easy miles. Changed oil every 2,000 miles. It was a growly noise and mild clicking- not valve tapping. Took the ignition side apart and found that one of the balancer sprockets (which have a rubber coating on them to keep noise down was worn badly). Thought(hoped) that was the problem and replaced the sprokets. Several fellow KLR listers wrote me with possible solutions and I thank them for that. With the engine back together it started right up but the same noise was there. My next guess was a bad bearing. After exploring the cost of replacing bearings(and finding out that the ignition side main bearing cannot be replaced without replacing that side of the crankshaft) I opted to buy a used bottom end off of ebay. There is one on there every week and most go for 250-300 bucks + shipping. Thankfully this was the problem- the ignition side roller bearing. I took my original crankcase apart and the bearing rollers had been sliding on the race and made it dull which produced the growly noise and the clicking was the crankshaft rubbing one of the 3 screws holding the bearing race in place. I could hear the noises easily by turning the crankshaft by hand. One of the guys that wrote me said his 03 did this same thing at 20,000 miles. Has anyone else had this kind of problem? My bike had been running so good I thought it would go forever. Now I'm skittish about keeping the bike for fear of this happening again. I sure know how to work on a KLR engine now though. Just wondering if it is a design problem. John in Florida