Context
Arf honnestly i expect that i could help people with some tricks. Actually these scooters are sold for pieces in mass because of 1 major issue the butterfly body, which is containing CDI and injection management. This part is suffering of a lack of studies according heat dissipation, humidity…. And some solderings inside are leaving their fonctionnalities.
Let’s introduce you to the Keihin 16400-KRJ-792 :
This device grab multiple information and acting in fact of them.
Let’s opening it
Harder than expected, once you have unscrewed the 4 torx the task is not the same. The box is sealed with a flexible sealant :
And clearly i had to heat the cover to unglue it… this resulted to that :
Then i thought from there that i should draw something :
Still in debug…
Cleaning Time
OK to remove the sealant, nails and a bit of acetone with an old toothbrush did the trick. Now it’s ok :
PS : This pict is after resoldering… excuse me for bad aspect of them i did that late in the night and for testing purposes… and honnestly i was not expecting a nice issue.
The most important pins are :
Soldering station, flux and soldering paste or leaded solder are usefull. and toothbrush again…
Testing Time
With a debug cover to avoid troubles :
Printed in PLA just to have a small try.
another one in ASA-CF is ready for longer tests :
First start was ok and seems more reactive at throtle. Waiting for the road test.
to be continued..
EDIT 30/04/2026 - About 8km without any FI light. lets see if it stays like that.