I find this most perplexing. I replaced the plugs, the wires, the O2s and now cleaned the DKs. One DK was obviously dirty with grease on the armature (so I found the problem - no!). Each one of these steps helped smooth out the engine under acceleration, but then the shakes would come back. After the O2 sensors it ran acceptably well for over 4 weeks (still had a slight shake on acceleration). After the Dk cleaning it had some EML issues. Disconected and charged the battery, cleared out the codes per shogun instruction. Next day ran seemingly very well - fixed - no. Now two days later it will barely get me home, EML comes on etc. I filled the tank thinging maybe the primer pump is getting weak - no change. I guess next step is to monitor fuel pressure. It is not blowing black smoke so I gather it is not runnign rich. Maybe a fuel regulator or pump.

Any ideas?