Head lights go off when engine revs

Hi all I'm new to this forum. I have a problem with my kymco super 8 50 2t scooter. Last night I switched on the head lights as usual they came on but as soon as I revved the engine they go bright then go off. It's the same with the main beam. If I switch the lights off then back on they work but as soon as I rev the engine they go off again. I'm thinking it could be the voltage regulator but I wanted to see if anyone else had any ideas .
Any suggestions or advice much appreciated
Best wishes Will

 

Certainly sounds like the reg/rec.
Does the back light do the same?

 

Hi thanks for your reply I'm not sure I will have to check. I have tested the battery which was about 12.3v it rose to 13.8v when I started the engine. When I switch on the headlights the engine pulls down as though there is load on but once I rev it the headlights go to brighht then go out and the revs pick up again. If i switch off the lights then turn on again they come back on. I put a multi meter into the plug that fits onto the bulb and it will stay at 13v even when revved but I guesstimate because there is no actual load . The regulator gets hot within 5 mins as well.
Thanks again for you input
Best wishes Will

 

The reg/rec does get hot, that's normal. As long as it's not melting the connector socket.........

 

Hi it's Will thanks for your reply. I found some info on a kymco forum. It was the headlight control unit . The control unit has a pulse from the cdi unit when the engine revs which switches the lights to full power then back to half power when the revs drop. Anyway it is possible to bypass it by unplugging it and bridging the connector with 2 lengths of wire. It works fine just means the lights stay bright on idle which could drain the battery if stationery for long periods with the lights on . The journey it does is half an hour run most of which is at full speed so hopefully not a problem. I can order a part but £50 and apparently they are something that's prone to failing.
Best wishes Will