| Another little trick seeing were all playing with dremils..i call them porting tool or die grinders ...the ignition pick up coil (the little black plasic box) ,thats under your ignition cover,close to the front sprocket has 2 screews holding it into place remove it and make the 2 holes oval by filing or using you dremil so you can slide or move the pickup coil towards the rotation of the flywheel..which will advance your ignition timing...to move the pick up coil even futher you will need to remove some of the alloy legs of the stator plate were the sreews go into..at the end of all that, before you retention the 2 sceews ...on the flywheel there is a small round dimple that passes that black pick up coil , make sure there is a gap of a business card thickness between them... then tention the 2 screews...you will gain about 3-4 derees in igntion timing giving you more throttle responce, it will get rid of flat spots in your carby and it will reve up cleaner and quicker. However if you have some cash..buy a inner ignition rotor kit i think their about a 100 bucks .Another trick get a cdi box off a chinese 50cc four stroke mini bike and plug it in your 125cc,140cc,150cc, pit machine (this only works if the electrical plug is the same conection) you will gain 2-3000 rpm higher reves....  | 
.....go you good thing
Linear Mode
