POI,
The only other reason it won't run is there may be something wrong with the carby body. Rare but not impossible, of the hundreds I have modified I have had 5 or 6 that for some reason just would not work so the percentage is low but there is always that chance. I have boxes of parts G4/LM and I just grab whatever I need, doesn't matter what they are. I do have to fit an idle stop screw in the G4 cam to prevent them travelling too far and allowing the cable to let go.
