Skip to main content

Keihin SPJ carb on a Rs125 nf4 bike

The SPJ carb from a later RS125 bike can be fitted on an earlier NF4 bike without much issues. The carb collar is a tight fit though removing the carb from the frame looks to be much easier than the stock PJ due to the shorter body. The throttle cable fitment clears the frame nicely as well. Most probably just the fitment of the carb without a proper electronic conversion from later bikes doesn't worth the hassle and the cost but it can still be used nonetheless. 


  1. Hello there , do you have a way to activate the powerjet ?

  2. Not for now. I was thinking to use a device based on an Arduino or something but the powerjets are very simple on/off switches and can be easily controlled with simple electronics. Only issue is making the unit programmable depending on the revs and closing them the exact time for the overev.


Post a Comment