Help needed plz.



I have a complete re-newed  pk engine with electronic ignition.

Setup is :

dr75cc cylinderkit
tecnigas chrome banana 
16.10 SHB carburettor

the main jet in it at the moment is 60. when I drive full throttle,  I can drive about 70km/h on the speedo, but several seconds later, it reduces to 60km/h on the speedo.

You can compare it like when you start your scoot cold, and pull the choke out and you drive about 100meters.


also, the ignition is standard and is mounted on the little line on the engine and the ignition, do I have to change this?


Does anyone can help me with the jetting? I don't know which jet is the best to use with this setup..





Drive until the engine is warm. Then drive full throlle en kill it! Stop on the spot and chenk your bougie. When your bougie is black the jet is to big, when it is white the jet is to smal