TOPIC:

Anyone have a writeup on installing a relay to delay headlight from switching on immediately to help bike start easier?

rdbhere2 wrote: Anyone have a writeup on installing a relay to delay headlight from switching on immediately to help bike start easier?

You shouldn't need to go to this extreme. The headlight should only be 65 watts (volts X amps = watts) so the headlight should only draw just over 5 amps which is peanuts compared to the cranking amps. There should be plenty of reserve in the battery to compensate for this draw during cranking.

My 1982 Yamaha 650 had a factory headlight relay that turned on after the bike started. It really saves the battery life on cold starts. I have a dry cell battery in my Kz1300. Not really a problem with the dry cell.I just thought it was a great idea.

It is quite easy to do.
I would recommend a relay for high and another for lo beam so as to remove the strain from the switch.
Once that is done put a relay in the feed wire for the hi and lo beam relays that is controlled by the wire that usually feeds the switch on the handlebars and instead of connecting the earth side direct to earth connect it to the starter terminal.
Explanation is that the starter has a very low resistance and makes an effective earth but when you press the start button that terminal goes to 12 volts which makes the relay drop out and the headlight goes off and as soon as the bike starts and you release the starter button the relay engages and the lights come on.