explorette

as im new to biking, not the best gear, Ixon waterproof textile trousers, alpinestars jacket and some cheap name gloves which are pretty good.

Hi, new to biking and just bought myself a 1993 sr125. everything is fine with it except when revving high the lights seem to dim a bit. im wondering if its the earth wire that needs a bit of tinkering or a problem with the battery? When revving normally the lights to brighten which, i think, suggests the battery is running fine. any help would be great as the haynes manual doesnt suggest this problem anywhere in it. Also, any clue where the earth lead is situated about? XD