Does anyone have this installed on their 400ex? I saw one on ebay and was interested in how much HP gain.

 

I have a built 416 motor and the Lectron made the biggest difference on my bike. It's hard to fit and hard to deal with, but i think it performs just as good as any other carb. On GT thunder websites they do dyno horsepower sheets and a lectron carb gave an extra 6 horses to a built motor. You will like the carb, but if you have the money get the FCR.