Dim lights conversion kit hp4


I am trying to put an electronic conversion kit (art, J50016000) to my primavera (6v points). The engine starts and runs ok but the lights are very dim. If I disconet the regulator (that was included in the kit) the lights are very powerfull, they blow in seconds. Once I reconnect the regulator the lights come down. Are the hp4 magnets powerfull enough? If I connect a bulb directly from the startor cables it sems to be very bright, they even blow. Is the regulator faulty?
Any help please!


Sounds as though your regulator is overcompensating and not providing the full charge to the lights ( I think total wattage is 35w for the lighting but can’t remember exactly). I have 3 pin 12volt/80watt regulator on my ET3 electronic and it works fine.

I’m not great with electical probs though and personally I’d ring SIP who can verify the wiring colours and connections on your new loom ( I assume you are using a new loom) . they may send you a replacement regulator. Try to lend a friends regulator first though.

Good Luck

The lights are not just less powerfull, they almost don’t exist!!!
I am sure something is wrong!
Any advise?


Thanks for your answer,

I have tried even to connect all the earths to one of the flywheel cover screws, just to check that wasn’t the problem, but nothing was better. I tried also to check with a bulb directly from the stator output wires but as I tell you, but when I conect the regulator the light go down, and if don’t conect it the ligth blow. ???
My HP4 comes whiht only one woodruff keyway, and it sounds very very well, like a cross bike!!! I’m looking to drive it, but I also need the lights!!! I need it to get me home also.

Please any light on this [;)]!!!

San Sebastian.



Sadly I'm back from hollidays. Finally the regulator was faulty. I tryed with other used in a pks and it works fine.

To SIP: What should I do with the one that came in the kit?

Thank you!




Basque Country.

Thank you for your answer,

I have not changed the loom. Why it should be necessaire? Can’t I adapt the old one? I have phoned sip but most of people are on holidays. I’ll try to check with another regulator and see what happens. For now I go on holidays for a week, after that I will tell you what happened. Meanwhile if someone has any idea please let me know.


my hp4 gives less powerful lighting, but hey , the sound of engine pickup more than mkes up for this

If i was faced with this quandry. !st I’d check all my connections had good clean earthing points (including the regulator) , then I’d try a spare regulator on it to see if that was the fault. try a testmeter on the two stator lighting coil wires to check sufficient wattage was being delivered. i doubt your magnets are at fault (even tho hp4 lighting generally isn’t that bright ) , good luck.

As a matter of interest did ur hp4 come with 2 woodruff keyways ? which one do you use ?