Wolfgang, again thanks for your reply. Funny you should mention the power. When I built the car I adjusted the throttle stop to 50% as a precaution. It has never gone beyond 50% so never got into power enrichment - air to fuel is always controlled by O2 sensors. The performance at 50% is incredible and more than a normal person needs . Nice to know though that a big power increase is available if someone is young and courageous enough to adjust the throttle stop up.