I just put new plugs in and rode it about 30 miles (55-65mpr) It sat for about 8 hours, then after about 5 miles it acted like it was running on 2 cylinders and when reved it has a rumble instead of a nice clean sounding rev.Its putting out alot dark gray smoke not really white or black. Any ideas on where to start. I can give more info but i'll start with this.

 

Anything?

 

have you checked that you HT leads are on right? Are the new plugs gappedcorrectly?

 

Also, what plugs did you put in? are they too cold? are they resistor plugs? Did you change anything else aside from the plugs?

Dennis

 

Plug wires on wrong plugs?