Originally Posted by frostyuk
if you look at bartons experience with his 70degree berg from the husaberg adventure team (ok its a 570 but essentially the same engine as the 450/390) he's changing oil on average every 40 hours compared to the 15 hours in the manual and an oil filter every 2nd or 3rd oil change. he's clocked up over 20,000miles now with no ill affects and no need to adjust valves etc after riding back from the record attempt in south america back to north america, so these competition engines can be very good in a non race enviroment
Yes- similarly I have a friend who did over 17,000 miles on a KTM400EXC (admittedly the older RFS design) trail riding and traveling in both Spain and Morocco, with nothing but regular oil changes and a valve check once a year...
Even her current generation 400EXC has been to Spain and back with no problems - well, other than the limited comfort from the stock seat... that engine is sound too...