headlight on/switch off

[jdn40]

I noticed the other day when i try to kick start the 78 xs650s that the head light comes on while i go thru the kick and then shuts off with the switch in the off position . If i try to start it with the electric starter it doesn't do it is this normal ? I have been having a no spark problem and cant get it to run so I don't know if it would stay on while running .

[pamcopete]

jdn40,

The headlight is turned on automatically by the safety relay, which gets a small AC voltage from the alternator when the alternator starts to produce a voltage.

When you use the kick start, there is plenty of battery voltage available, so the safety relay and headlight come on briefly as you kick it, then releases when the engine does not start.

When you use the electric starter, the starter motor draws the battery down, so the headlight does not come on fully. but if the engine started, it would come on once the starter motor stops.

On later models, the safety relay has an extra relay for the headlight that latches on as soon as the alternator produces enough voltage, which is even more aggravating if you are trying to trouble shoot a no start condition.

In both cases, I would suggest that you disconnect your headlight until you have found the no start problem.

[5twins]

Disabling that safety relay on your '78 is as simple as unplugging one wire, the blue/black one. Then the handlebar on/off switch will function normally and all the time.

[jdn40]

Thanks guys , think the no spark is a coil problem . Where is the saftey relay located ? This free bike aint turnin out to be so free lol

[madmax]

Behind the right hand side panel, upper left corner next to the starter relay.

Max