Lifan 50cc monkeybike help wanted

[Fiddy@norway]

I've recently purchased a 50cc monkeybike clone with a 50cc lifan engine in it, this bike is plated as a moped here in norway, and I am in the process of squeezing more power out of it.

the intake has a line going from it to a box that looks like a sort of rectifier, anyone have any ideas what this line does??

 

[Minibiker05]

Ive nevver seen that before looks like a sensor like u would use for efi seams odd ive u disconnect it does the bike still run

 

[sean01]

yeah seems very odd, but maybe its some sort of advance retard system..

 

[The_GDFP]

Got to be a performance limiter of sorts to meet moped laws.

 

[nick1969]

I have the same on a Lifan based monkey. I found from the manufacturer it is a speed limiter, but yet to investigate how it works.