Yuminashi Powersport ECU Honda (OG MSX/GROM125 - WAVE125i (2013- ))

YUMINASHI POWERSPORTS ECU HONDA MSX 125

Installing the Yuminashi Powersports ECU is really something you want to do from the first day you are buying your bike because this easy to install and low-cost upgrade will transform your bike totally!...

Installing the Powersports ECU on an OG MSX/GROM is really child splay because the Powersports ECU has been specifically developed for the OG MSX/GROM125.
This means that with this ECU you won't need to repin the wires from your stock wire harness.

The install of the Yuminashi/Keihin ECU on the OG MSX/GROM125 is simply done with removing the stock ECU and replacing it with the new Yuminashi Powersports ECU. (If you want to install this ECU on the MSX/GROM125 SF or 2019 CRF110F PGM-FI, then please follow the repin guide below)...

● Once you installed the ECU there are 3 things you need to keep in mind:

1. There is a chance that your bike won't run correctly from the first time you start your bike since in closed loop it's capable of self-adjusting fuel trims and ignition tables while you ride to deliver an accurate and safe performance, it is a completely autonomous system....no more software updates, data cables, laptops, secondary sensors, building/searching or asking for maps needed.
   It will automatically learn and store the adjusted fuel trims and ignition tables in a closed loop by itself using the OEM O2 sensor already on the engine.
   So keep in mind that the first kilometres/miles you drive your bike/ECU will be in learning mode.
   
   
2. If you run a big bore kit with a 2 valve or 4 valve head, then you need to install a larger injector to compensate since the stock injector has it limits.
   
   
3. The Powersports ECU has the RPM limiter removed, which means that you won't see the RPM limit anymore at 9500RPM's
   We recommend to install our double valve springs set to avoid floating valves in the higher RPM zone. LINK 

※ Installing the Yuminashi 4th gear sports sprockets LINK would be the cherry on the cake in combination with the Powersports ECU.  

※ Keep in mind that around 80% throttle the ECU will run in open loop where the injector size need to be correct with your engine setup since it doesn't get a signal anymore from the O2 sensor and it won't be able to make corrections. 

※ If you have no wideband O2 gauge installed, or you simply have no experience with PGM-FI tuning, then a simple rule of thumb is that if your engine doesn't want to make RPM's, your injector size is too large, if your engine wants to make RPM's, but have bad low and middle RPM power, then your throttle body size is too large... 

Both situations are too avoid, and if the injector size isn't right or the throttle body isn't right, then the Yuminashi Powersports ECU can't generate a correct map for it...

※ We recommend to install the right size injector in combination with the Powersports ECU which we have available with 140cc, 150cc, 160cc, 170cc, 180cc, 190cc, 200cc/min and even more flow rates.

THIS VERSION OF THE POWERSPORTS ECU IS MENTIONED TO BE INSTALLED ON:

HONDA:

• BLADE 125i / SUPPRA X 125 PGM-FI
• BIZ 125 (2014- )
• MSX125/GROM125 (2013- )
• MSX125 SF / GROM125 SF (2017- ) ※Need to be repinned (please look for details below)
• WAVE125i (2014- )
• Z125 MONKEY (2018- ) ※Need to be repinned, buy only at your own responsibility, we don't provide information on how to do it, we never tested this combination yet!...

REPIN MSX 125 SF (2017-) para OG MSX 125 ECU: 

• PIN 18 SF (White / Blue) goes to PIN 22 (OG)
• PIN 22 SF (Yellow / Green) goes to PIN 28 (OG)
• PIN 28 SF (Yellow / Orange) goes to PIN 20 (OG)

NOTE:

• This ECU is a replacement for OEM #38770-K26-901
• Keep in mind that this ECU was designed for the OG MSX/GROM125, not for the MSX/GROM SF or Z125 Monkey, so if you install the Powersports ECU on an MSX125 SF, GROM125 SF or Z125 Monkey, then this is on your own responsibility and you will need to repin the stock wire harness.
• All ECU's are tested before shipping out to be sure all ECU's are functioning properly before shipping them out. If you decide to repin the ECU, then keep in mind that this is 100% on your own full responsibility since Yuminashi can't check how well you have executed this task.