siebenrock upgrade 800 >1000 r 80 gs

[Jake]

I have a 1991 r80gs and am wondering if anyone has done the siebenrock upgrade. I carried this out and have now covered about 4500 kms since doing the conversion. The bike has a definite increase in torque and power and feels much better except for one area fully loaded under load/acceleration there is the metalic pinging a bit like pinking - similar sound even at 60/70 mph top gear roll on acceleration.
As per the siebenrock instructions no changes have been made to valves/carbs or timing this did not happen at all with the stock barrels also a marked increase in oil consumption - upto about 1 ltr /1500km before this the bikes use of oil was very low at best. I accept that the running in period for the pistons etc may have given to this rise in oil consumption. The plugs are a tiny bit oily around the outer edges(I mean just minute traces) but nothing to worrying.So far the bike has 73000kms and otherwise runs perfect any suggestions advice or experience would be great before I contact siebenrock for there point of view. I know I can always go back to standard barrels if need be. Ta Jake.