EFI Controller for PCX-125

Slickvic · Post by **Slickvic** » Thu Mar 07, 2013 7:15 am

I found a posting on another forum that led me to this US based company that sells a EFI controller for the PCX-125.
This Controller only adjusts fuel. It is a piggy-back controller meaning it is only making adjustments on top of the stock ECU map.

http://www.electronicjetkit.com/Scooter ... er=8110043

Note: I am not endorsing this product. I am merely passing the info along.

BTW, the forum which I learned about this claimed a 1HP gain:
http://www.motorcycle.in.th/forum/viewt ... topic=3077

uploader · Post by **uploader** » Thu Mar 07, 2013 3:53 pm

I can't see this improving the Honda PCX PGM-FI fuel injection system but Please, prove me wrong

maddiedog · Post by **maddiedog** » Fri Mar 08, 2013 1:58 pm

Uploader -- It might work, but at the expense of fuel economy. Honda factory-tunes bikes to give what they think is the best combination of economy and power by regulating the fuel flow on the FI system. Dumping fuel in will naturally add power, but your economy might tank as a result.

Cascanciu · Post by **Cascanciu** » Thu Apr 25, 2013 3:32 pm

Unless the PCX is running very lean (likely) dumping more fuel in won't make any noticeable difference. Best performance, if I'm not mistaken, is obtained when the air to fuel ratio is at or close to stoichiometric values (14.7 to 1). Running rich would worsen performance. Running too lean is also dangerous because the temperatures in the chamber/exhaust increase dramatically.

IMHO, that box could produce some gain if it could play both with the AFR and the ignition timing, and it looks like it does not.

Alibally · Post by **Alibally** » Thu Apr 25, 2013 5:33 pm

1HP. Wowwza. Mind due that's nearly 10%. As said in the last post the air fuel ratio should be maintained so increased fuelling requires a better volumetric efficiency to keep everything it correct otherwise you will get problems. I suppose a rich mixture is better than a lean one if you don't want engine damage due to pinking.

dem0nk1d · Post by **dem0nk1d** » Wed Feb 12, 2014 10:59 pm

Note that running rich can damage the motor by washing the oil viscosity away from the cylinder walls. Adding premature wear on the piston skirts and cylinder walls. But it will last longer than running lean, that's for sure!

Mgalutia88 · Post by **Mgalutia88** » Thu Feb 13, 2014 1:50 am

Best performance in na applications is at 12:1 and in boosted applications at 8:1-10:1 where fuel is also used to cool the combustion chamber to prevents spark knock. Running rich causes carbon build up and other issues but is also easier on the engine b/c it runs cooler at a proper rich mixture. Running lean results in combustion chamber temps high enough to burn holes in pistons and burn valves. Make no mistake, 14.7:1 ratio provides the least emissions.

Pcxdemon put on an o2 gauge and shot a test video under his 170cc thread. The factory computer runs down to 12:1 for WOT and up to 16:1 for cruising and everywhere in between.

Pcxdemon · Post by **Pcxdemon** » Thu Feb 13, 2014 6:15 am

Mgalutia88 wrote:Best performance in na applications is at 12:1 and in boosted applications at 8:1-10:1 where fuel is also used to cool the combustion chamber to prevents spark knock. Running rich causes carbon build up and other issues but is also easier on the engine b/c it runs cooler at a proper rich mixture. Running lean results in combustion chamber temps high enough to burn holes in pistons and burn valves. Make no mistake, 14.7:1 ratio provides the least emissions.

Pcxdemon put on an o2 gauge and shot a test video under his 170cc thread. The factory computer runs down to 12:1 for WOT and up to 16:1 for cruising and everywhere in between.

Best most powerful mixture is at 11.2:1 according to the google searches,maybe not most economical but if one is after performance than that doesnt matter,doest it..
Pcx Pgm-fi is awesome at what it can keep up with,170cc bore,big throttle body, pod filter,exhaust and it still is able to adjust fuel accordingly...all i upgraded was a injector. When cruising my AFR meter keeps constantly shuffling between 13.something:1 and up to 16:1 but mainly it seems to stick the longest at 14.7:1. The shuffling part is due to my guess is engine cycle from the time it injects fuel and it burns it out as the o2 sensor is literally right in the head exhaust port.If its fitted bit further down the stream like exhaust header and perhaps proper wide band o2 sensor was used the figures would be more stable and less prone to shuffling...

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