650ed wrote:
M_a_t_t wrote: ............... I think after 74 all headlights on motorcycles are required to be on when the motorcycle is running.
Not so. I believe that requirement started in 1978. My 1977 KZ650 came with an ON/OFF headlight switch. Ed
My old '82 KZ750-LTD did not have a headlight on/off switch. It was always on. It has the same right hand side control part number as t he '81 model. So I don't think he can turn it off.
In California, a law was passed in 1978 that motorcycles must be equipped with at least 1 and not more than 2 head-lamps that turn on automatically when the engine is started and remain lighted while the engine is running. What this means is that it is illegal in California for the lights to be able to be turned off if the motorcycle is from 1978 or later. I would suggest this is why your '77 and his and my early '80s KZ750s don't have that ability.
While yes it's California, and California isn't everywhere, it's cheaper to to just make them all the same way, especially given that most states at the time (if not all) already required the light to be turned on at all times, even in the day time.
That said, I'm riding around on a bike from 10 years later that has the ability to switch off the headlights... but it's also a bike that was made exclusively for police... and the headlight being on all the time would make running a speed trap a bit harder.
All of that said... an '81 KZ750 should have more than enough juice to spare to run any H4 bulb, seeing as how just being stock it has a 60+ watt halogen H4 bulb. Seriously, if removing the headlight bulb makes the bike run and putting it in makes it not run, you have something seriously wrong with the electrical system on the bike and buying an LED is like putting a bandaid on a hemophiliac with a severed artery. You're running on time bomb regardless of what bulb you use. Be smart and figure out where the problem in your electrical system is.
At that age, I wouldn't be surprised if it's a voltage regulator issue. Doubly so if you put a lithium ion battery in it... I did that to my KZ1000P and now I'm having electrical issues a couple months later due to the voltage regulator burning out...