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Honda Trail 125 Forum

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Best non-BBK power mods?

Flash

Member
Joined
Mar 20, 2024
Messages
81
Location
Canada
Well, I got the new injector installed and took a short spin, ~12 mile run. And it has changed quite a bit, despite it only being a few miles! For now, it's seems to be somewhat hesitant to go from a dead stop, but does not mind being near WOT with 70-95% throttle being roughly 45-50mph. WOT is still underwhelming, but it's a 125. The engine also runs a lot cooler, the throttle body and clutch cover not getting nearly as hot as with the stock injector (which was my primary cause for concern)! It does smell a bit rich while idle (no visible smoke), but as others have said that will change with time, so I'm not too worried about it for now. Will report later on... if the clouds will let me!
What was the part number on your new injector?
 

Flash

Member
Joined
Mar 20, 2024
Messages
81
Location
Canada
I am still trying to find the real data on different injectors. The PCX 150 is too rich and the stock trail is to lean. Need the one in between.
 

FizzBuzz3000

Member
Joined
Sep 6, 2023
Messages
57
Location
Somewhere in Central Minnesota
Well, after a few tests, the new injector is not that good. It runs too rich for the stock fuel map when open-loop and the closed loop has to constantly readjust itself after the bike has warmed up. There is noticeable power loss near WOT, and you can smell un-burnt fuel leaving the exhaust. I didn't check the sparkplug, but I am going to assume it was getting carbonized. If the #16450-K76-T61 '23 stock GROM injector is flowing at a minimum of 105cc/min, you probably want no more than 95cc/min flow rate if using a free-flowing exhaust and stock air filter.

Sucks I'm out $40...
 

Flash

Member
Joined
Mar 20, 2024
Messages
81
Location
Canada
Egads up in Canada that Grom injector sells for $180. That's why I did not want to buy it on a curiosity test whim. I paid $75 for the PCX150 and it is too rich. It is aledged to flow 140cc min. What I don't understand is the Grom injector is supposed to flow (105-115cc min) less than the PCX. Stock Trail injector is supposed to be 90 cc min. The three versions do not line up according to your field experience and mine. Mine should be flooding way worse than what you are exoericing. AFR has it at 10.9 -11.5 @ WOT approaching the 3/4 shift at 7000 rpm. The same situation was with stock inject it was reading 13.1-13.3 which is on the lean side of power mixture for sure. Ideal I was understanding is 12.5 full load. Maybe I got a lean PCX and you got a rich Grom version. Now how to test without throwing money down the perfect mixture money pit.
 
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