2002 rx pops out of exhaust at higher rpms and has blackish looking smoke come out when it pops. I pulled the carbs 3 times and everything looks good , New fuel lines and selector switch. Reed valves look good. Checked timing with induction light and it was lined up with the pointer until about 4k and would go slightly advanced. Stator is charging good and checked for ac volts and it was about 300 mvolts. Checked all the rubber exhaust hoses. Drilled my rave valves and eliminated the solenoid and plugged the pulse line on the block. Only other thing I know of i can try is another mpem. The black smoke makes me think fuel but I've checked the carbs and everything looks just as it should. Any ideas?