2005 Aprilia SR50 R Factory Ditech

I need help,

I upgraded to the Malossi 70cc Kit with reeds and Ecu, It ran very well for about 2000klm's reaching a top speed of around 95KPH. Now I have a huge problem the bike starts everytime but it won't rev over 3500-4000rpm. I have checked and cleaned and replaced almost everything like Spark plug and Injector and even bought the malossi 70cc pipe but still doesn't help. I think its a problem with the Malossi ECU?? What I would like to do is convert it to CARB some how, What is exactly is needed? I want to do this ASAP as the last 4 months the SCOOT has just been sitting as it won't drive over 4000RPM it just coughs and pops at those revs:(

Please any help would be much appreciated as I love this scooter and I am pulling my hair out trying to figure out what has gone wrong !

Found this below

http://www.youtube.com/watch?v=JcmZClOrIew

how do i do it, as the ditech is driving me nuts. or is there a way of remideing my problem easier?