I have previously written (here and here) about Aaron S. on advrider.com who rode his KTM 500 EXC around New Zealand, shipped it to South America, and then rode it all the way to Alaska. Still not finished, after touring Alaska Aaron headed back to the lower 48 and spent some time exploring Colorado and Utah. From there he returned to Oregon and currently has 854 hours on his 500. How is it holding up?

‘After the last couple times out on my bike I have decided it’s time for a rebuild. She is starting to smoke more than I would like on start up and I have started to use oil between changes so I’ll be ordering up some parts in the next week. Currently it has about 854 hours and I have a weekend of riding coming up so it might reach 860 odd and that is probably going to be it for the girl. Now what to do with that legendary piston. Perhaps a little box like you would put a famous baseball in or something huh.”

That’s pretty impressive to me – 854 hours and tens of thousands of kilometers on a motor that KTM recommends changing the piston, valves, valve springs, valve spring seals, connecting rod, conrod bearing, crank pin, and all engine bearings every 135 operating hours. Your calculator will confirm that 854 hours is more than 6x the recommended 135 hours.

What work has Aaron done on his motor in that 854 hours? He adjusted the valves once and has changed out the clutch plates a couple of times.

I hope my 500 EXC performs as reliably as Aaron’s has.

Here is Aaron’s bike in South America