Hello I have problems between 5000 and 6000 rpm in my NC35 . The bike lose power in this rpm and is slow . Under 6000 and down 5000 is perfect . Is has spark plug news and air filter new . Carburetors are cleaned

Does it rev fine past 6000 rpm? if not then check the orange and blue wire from the cdi is connected to 12v+

Hello , yes the bike is good up of 6000 rpm , and under 5000 is perfect I have problem betweenn 5000 and 6000

My money is on the carbs. Sounds like you are hitting the flat spot.

I don't think so. When the reg/rec goes south, it usually cooks the battery. That makes the bike stop running altogether. The 5-6K flat spot is well documented on these bikes. Take a look at the carb guide sticky posts at the top of the V4 workshop section... viewforum.php?f=24