I took my 2003 for a ride, and about 20-25 miles into it it started to miss bad, and would die when the clutch was pulled in. It ran fine up to this point, and all I did was put new plugs in it, and add some good fuel. It was a nice easy ride too, I was going crazy with it. When it idles you don't see the black smoke, but any throttle that is given it blows it out badly. It compares to the smoke from a diesel truck under load to give you an example. It starts and idles on its own when cold, but when warm you can keep it running my giving it WOT and hold the RPM's to 2-2500. I cannot find the plugs that were in it, but replaced them with standard NGK CR8E's. I just replaced them 2 days ago when I had time to work on it with CR7E's, and checked for spark and the boots to make sure I didn't damage them, it had good spark and the boots were ok. It is burning a little oil and a friend stopped by and thought it might be a valve seal that had gone bad causing the smoke and plug almost immediately fouling, but it is pure black smoke, and when I pulled the CR8E's out I had replaced with the ones that were in it when purchased, the new ones were black after 40 miles tops. I used a little brake cleaner and most of the black came off easily. Ive been going through my service manual, but wanted any help on something obvious it may be..Any help would be great.