I have a 70 dt250 project I need to wire lights on I heard I can put a regulator off the coil power to run a battery and lights my ? Is what size regulator do I need 

'I heard its a 250 one.'

Sarcasm? Yes, but only by example. You have given as much information in your question as I have in my reply.

Please, we are not psychic, were just people who like bikes and want to help people out and have a laugh, one line questions are for google. Feel free to use the intro section so say hi and let us know your plans, even start a build thread in the projects area, that will get you help on all aspects and normally save cash on parts, even get parts through members.

The op, mine may be the only reply.