The other is that there is something strange about the timing. At low power things appear fine; switching off leading ignition has more effect than switching off trailing, as expected. At operating power levels, however; switching off leading has almost no noticeable effect; whereas switching off trailing drops the rpm by 400+ rpm - which suggests that the timing is very late. Yet advancing the timing via mode 8 does not make any improvement. What is wrong with this picture? It is possible that the added filters caused a delay in the timing, although analysis suggests the effect would be small. Why doesn't advancing the timing improve the power? Is there a timing change to one set of coils associated with disabling the other? We are removing the filtering capacitors from the ignition circuits as a test to see what the effect is.