How to run electric fuel pump with Lifan 110cc+Regulator

[Henkka]

I have been struggling a few days now with fitting the electric fuel pump to lifan 110cc engine. The problem is that I can get light bulb working properly, but my 12VDC fuel pump does not run. I am not using battery on my setup.

I attached a regulator to the engine, using this wiring guide.
http://api.24mx.se/File/Image.ashx?oid=1342&type=img

Between the red wire and the green one, I can get 7V DC measured on idle speed. When I increase the motor speed, the voltage rises. When the voltage reaches 12V, it drops down to 7...8V. I tested with the 12V 55W H7 bulb, and it works nicely on every engine speed. But my fuel pump doesn't say anything.

Is there something wrong with my wiring? Or is the regulated 12V some kind of "un pure" DC, and preventing the fuel pump to run? If someone has any ideas how I can get it working, I would be wery pleased.

My regulator is this:
http://www.24mx.com/pitbike/p/rectifier/13375/electronics/k120/

 

[my67xr]

im pretty sure you will need to run a capacitor in the circuit if you dont run a battery.
do you have an electronics store close by?
jaycar or the like?

buy a 25 volt 3000 Uf capacitor and wire that into the circuit.
you will see the negative side on the cap, it is marked with a line down that side.



can i ask why you dont want to run a battery?
and what sort of fuel pump do you want to run?
do you have any pictures?

cheers, craig

 

[Henkka]

Thanks for the quick reply.

I have a electronics store next to my work place.
http://www.bebek.fi

How should the capacitor be fitted to the circuit? In parallel with the fuel pump, between the rectifier and the pump? On the other hand, will the small 12V battery between the pump and regulator solve the case? I was just wondering that will my regulator charge the battery, because it will reach only 12,00V at maximum, and battery needs 12,5...13V to be charged...

The reason I don't have a battery at the moment, is that I don't have any free space for that on my setup.

Edit: I picked up now 2pcs 4700uF 35V capacitors and I'll try with these.

-Henkka