Originally Posted by ericGSsti
Hi lads, new to KTM and to the 640. I took it for a spin today and at 120 kph it was revving at around 7000 rpm. I got off the motor way as soon as I could as it didn't fell normal. The lad that sol it to me said he change the sprockets on the bike dropping a tooth or two. Would that have this effect on the revs at motor way speeds. If so by fitting an original chain and sprocket would it return to normal. What is normal for these bikes?
Yes, if you fit the stock 16/42 ratio your bike will show revs between 5500-6000 at 120 KPH... With the gearing you have now I bet the bike is a tractor...