Virago Headlight Problem

BaroldGene.RemoveThis@gmail.com wrote:
> So I have an 83 Virago 750. Headlight will turn on when the key is in
> and on, and it stays on during starting. But as soon as the bike is
> on the headlight dies. The taillight is still on, just no headlight.
> I sat on it today and discovered that the light will flicker at almost
> exactly 2000 RPM. More and it dies, below ~1800 and it dies. But at
> 2000 RPM it will flicker.
>
> The starter button is rather old and doesn't stick out anymore, but I
> took it apart and pushed it out with no help. I haven't really
> checked the wiring out, but this doesn't seem a likely culprit as the
> headlight works as long as the bike isn't running. I tried shorting a
> few of the relays, to no avail.
>
> Any suggestions?
>

Either buy a replacement starter button and spring from someplace like
PartsNMore or OldBikeBarn, or just drop $45 and get a generic control
replacement at MikesXS.com.
 >> Stay informed about: Virago Headlight Problem 

On Jul 10, 8:09 am, "Albrecht via MotorcycleKB.com" <u33665@uwe>
wrote:
> BaroldG....TakeThisOut@gmail.com wrote:
> >So I have an 83 Virago 750. Headlight will turn on when the key is in
> >and on, and it stays on during starting. But as soon as the bike is
> >on the headlight dies. The taillight is still on, just no headlight.
> >I sat on it today and discovered that the light will flicker at almost
> >exactly 2000 RPM. More and it dies, below ~1800 and it dies. But at
> >2000 RPM it will flicker.
>
> The symptoms indicate a bad connection somewhere in the supply to the
> ignition bus.
>
> The ignition bus is not yellow, it isn't a school bus. The ignition bus is
> the source of power to everything that works when the ignition key is turned
> on.
>
> There are at least two sets of contacts in the ignition switch. One set of
> contacts
> powers the tail light and the other set of contacts powers the ignition bus
> which supplies power to the headlight, brake light, instrument lights, horn,
> turn signals, etc.
>
> Typically a red wire will come from the rectifier regulator to the battery
> positive terminal and then another red wire with an inline fuse will go to
> the ignition switch.
>
> Then a wire of a different color goes back to the fuse panel to supply the
> ignition bus. Suzuki always used an orange wire, your Yamaha may be different.
> Suzuki always used a brown wire to go to the tail light.
>
> You can follow out the wires from the head light fuse to the headlight
> connector and also check out the grounding wire from the headlight connector.
>
> But I suspect the problem may be in the ignition switch itself. I have had at
> least three ignition switches get so hot they burned the insulation of the
> wires going to them, or melted the solder attaching the wires to the switch.
>
> Why does the headlight work, with the engine off, if the switch is defective?
>
> The burnt contacts have high resistance, and the resistance gets even higher
> when the engine is running and the voltage to the ignition bus rises from
> 12~volts
> to 14.5 volts.
>
> The I squared R loss across the bad contacts increases and nothing gets to
> the headlight.
>
> Another possibility is that one of the production break connectors has bad
> contacts. Production breaks are connectors in the wiring harness that are
> there just to make manufacturing assembly simpler. They are rarely ever
> disconnected by anybody, not even a $tealer$hip mechanic.
>
> Production breaks will be in inconvenient places, like up under the gas tank.
>
> --
> Message posted viahttp://www.motorcyclekb.com

What steps can I take to determine if a new starter switch is
definitely the problem? A friend mentioned that it could be a bad
regulator thus causing the light to come on only at a certain RPM. I
plan to take that off and check it out a bit. But I am on a college
student budget and can't afford to keep buying parts that don't fix
the problem. haha.
 >> Stay informed about: Virago Headlight Problem 

<BaroldGene.TakeThisOut@gmail.com> wrote

> But I am on a college
> student budget and can't afford to keep buying parts that don't fix
> the problem. haha.
>
Maybe it's time you take a course in logic and reasoning!
In this case, the most likely causes are also the cheapest to fix.
Get a new bulb. If that doesn't fix it, then you have a spare.
Check for loose or chaffed wires.

Ask one of your Professors what Ocham's Razor is!
 >> Stay informed about: Virago Headlight Problem 

<BaroldGene DeleteThis @gmail.com> wrote:

> So I have an 83 Virago 750. Headlight will turn on when the key is in
> and on, and it stays on during starting. But as soon as the bike is
> on the headlight dies. The taillight is still on, just no headlight.
> I sat on it today and discovered that the light will flicker at almost
> exactly 2000 RPM. More and it dies, below ~1800 and it dies. But at
> 2000 RPM it will flicker.
>
> The starter button is rather old and doesn't stick out anymore, but I
> took it apart and pushed it out with no help. I haven't really
> checked the wiring out, but this doesn't seem a likely culprit as the
> headlight works as long as the bike isn't running. I tried shorting a
> few of the relays, to no avail.
>
> Any suggestions?

Look, the Virago has a system that cuts the headlight when you press the
starter button, so as not to reduce the current getting to the starter
motor. The engine fires, you release the button, the light comes on
again.

If the headlight is working fine when the engine is not running, then it
is one of two things:

1. A bulb about to go, or a dicky connection that makes and breaks at a
critical rpm.
2. The duff starter button switch rattling in the housing and making and
breaking the contact. But if that were the case you ought to hear the
starter motor trying to engage as well, unless you have to pull in the
clutch as well before the starter spins.

The starter buttons on these old Yamahas are notorious for falling out.




--
BMW K1100LT 750SS CB400F CD250 SL125
GAGARPHOF#30 GHPOTHUF#1 BOTAFOT#60 ANORAK#06 YTC#3
BOF#30 WUSS#5 The bells, the bells.....
 >> Stay informed about: Virago Headlight Problem 

On Jul 11, 2:28 am, chateau.murray.takethis... DeleteThis @dsl.pipex.com (The
Older Gentleman) wrote:
> <BaroldG... DeleteThis @gmail.com> wrote:
> > So I have an 83 Virago 750. Headlight will turn on when the key is in
> > and on, and it stays on during starting. But as soon as the bike is
> > on the headlight dies. The taillight is still on, just no headlight.
> > I sat on it today and discovered that the light will flicker at almost
> > exactly 2000 RPM. More and it dies, below ~1800 and it dies. But at
> > 2000 RPM it will flicker.
>
> > The starter button is rather old and doesn't stick out anymore, but I
> > took it apart and pushed it out with no help. I haven't really
> > checked the wiring out, but this doesn't seem a likely culprit as the
> > headlight works as long as the bike isn't running. I tried shorting a
> > few of the relays, to no avail.
>
> > Any suggestions?
>
> Look, the Virago has a system that cuts the headlight when you press the
> starter button, so as not to reduce the current getting to the starter
> motor. The engine fires, you release the button, the light comes on
> again.
>
> If the headlight is working fine when the engine is not running, then it
> is one of two things:
>
> 1. A bulb about to go, or a dicky connection that makes and breaks at a
> critical rpm.
> 2. The duff starter button switch rattling in the housing and making and
> breaking the contact. But if that were the case you ought to hear the
> starter motor trying to engage as well, unless you have to pull in the
> clutch as well before the starter spins.
>
> The starter buttons on these old Yamahas are notorious for falling out.
>
> --
> BMW K1100LT 750SS CB400F CD250 SL125
> GAGARPHOF#30 GHPOTHUF#1 BOTAFOT#60 ANORAK#06 YTC#3
> BOF#30 WUSS#5 The bells, the bells.....

I understand the starter cut-off. Funny thing is, the light stays on
during start-up. The whole time the starter is cranking the light is
on, albeit flickering.

I have no problem buying a bulb and keeping a spare, but buying things
like regulators and starter-switch assemblies isn't overly practical
and having a spare of those doesn't help me much.

And I understand Ocham's Razor. Although I have to say Wikipedia is
far more useful than your average professor in explaining that one.

My best guess at this point is a loose wire or the regulator. The
starter cut-off doesn't seem likely as everything else functions just
fine. Its just the headlight. And the fact that it is 2000 RPM
exactly that makes the headlight flicker makes me think it is a
regulator problem, not a problem with a relay. I need to find some
time to work on it, I just haven't yet. Especially as it gets me from
A to B for the moment.

Is there a way to hard wire the light so as to make it work apart from
the starter cut-off, etc.? Hell, I wouldn't mind having to manually
turn it on after the bike is on. At this point I just need a light in
case I get caught somewhere at night and have to ride home.

Another note. When the light flickers, it seems to be somewhat
coordinated with the RPM. During startup it will flicker in time with
the motor turning over. And when it flickers around 2000 RPM it will
do so somewhat in time with the RPM. If it drops to 1900 RPM it will
flicker a bit slower. Its hard to tell this for sure as it is such a
tight range that it will actually flicker when the bike is running.
But it appears to do this.

Not sure if that changes anything.
 >> Stay informed about: Virago Headlight Problem