Did you acquire Ignitech CDI units from the manufacturer or a distributor? They were on your machine when purchased? You have equipped your machine with an injection?  The CDI curve and settings do not comply with the maximum recommended by ROTAX or are not optimized for injection! 
You send them by post, we reprogram them and send them back to you within 48 hours!
Easier starting, lower and more stable idle (less traction on final...); elimination of the vibrating range (3000/3500rpm), reduction of consumption. compliance with ROTAX maximums