I bought the same one (Yamaha DT 50 2007) and I HAVE THE SAME PROBLEM you have. Modifying the exhaust is and changing the main jet to 90 95 or 100 is a good start but it is not enough...
The real problem of the new 2007 model is that it is restricted electronically on the CDI. The CDI refuses to go upper 8000 turns/minutes wich is totally stupid for a 2 stroke engine. The new model 2007 is now working like a cow...
At present I'm talking with my yamaha revendor who says he doesn't know yet what to do.
I also looked at the differences between the two models 2006 and 2007 and the CDI is a lot different (much more wires on the new 2007 model) so I don't know yet what to do... I think I'll study a way to change the CDI with a different one, I heared, but not sure, that the "TOP PERFORMANCE ducati CDI for minarelly am6" could work, but I'm not sure yet on how to mount this...
If anyone has THE SOLUTION or any DT50 2007 service manuel or electrical drawings, please let us know!!!
