[redyaris]

so far on this trip I have gone 803 miles and used 11.7 galons for a consumption rate of 68.6 mpg. What I have noticed is that at 110 km/hr at 4200rpm on the highway I use only 20% or less throatle,which is barley off idle. the light black deposit on the exhaust pipe suggests over fueling, I will have to install the O2 readout system to check and adjust the carb if that is true. I think I may be very close to the limit for this size engine & camshaft. I don't think I can lower the rpm without a change of cam profile to move the power/torque curve around. the engine is probably miles away from it's BSFC optimum at less than 20% thoatle at 110km/hr [68mph]. an other idea would be to find and install smaller carbs.