Scary electrical issue

[mrkil]

So I got a Sparx off egay
It was for triumph and I assumed it would be the same as the xs650 one......
Guess what....
It exploded between my legs. I had it mounted between the carbs just below.

Scared the crap outta me
Seems that the positive is the negative side like all lucas positive ground stuff...
The bike still runs fine and it didn't take anything down with it thank goodness

 

[TurboFarviknugn]

The one with 2 prongs is the + and the single prong is the -. Glad your ok !!!

 

[mrkil]

Notice how they have the negative painted red though. Thats what threw me :/

 

[tonyc]

Quite a few Brit bikes are wired just the opposite.

 

[mrkil]

Yeah i forgot about the positive ground in british vehicles......

 

[TurboFarviknugn]

Just for future reference IF in doubt put a digital voltage meter on it IF it is backwards it will give you a negative reading, if you got it right it'll just be numbers.

 

[ANLAF]

mrkil, wow! I am sorry to hear about your exploding Sparx. I have got two on the bike, not wired in yet. I'll heed the warning.

Good to hear nothing else went with the Sparx.

Anlaf

 

[ANLAF]

Turbofarviknugn, can you talk me through the test, again.

I have two bolted on the bike but not wired in yet. I just put the voltmeter on the connections both ways and got numbers both ways (nothing is wired in yet, but I may have earthed one side.

There are three connectors on mine, and it came with a note and diagram talking about British bikes having positive earth. What's the step-by-step check I don't end up getting a nasty shock like Mrkil?

Anlaf

 

[mrkil]

Thanks guys
I think what he is saying is that if it is wired backwards it will show negative numbers and wired properly it will show positive numbers.

 

[ANLAF]

Fellers, this is what came with my Sparx. Perhaps these should come with a warning of explosion if wired incorrectly.

Are all Sparks positive (or red) earth/ground?

Anlaf

 

[mrkil]

I'm not sure that you can run it that way.
British bikes don't ground on the negative but on the positive. The one I had was cor a triumh as well.

I'd like to know if there is a difference between an xs one and a brit.

 

[xjwmx]

It shouldn't matter if the bike is positive ground or not - as far as the cap is concerned the only thing that matters is which direction the current flows through it. Like if you had a LED, you'd still connect its positive to the positive of the battery even though that went through the frame instead of the minus going there.

The thing that's troubling is the negative has the red dot! If if really does. Maybe the cap was just defective? Or maybe it was in fact connected backward (red to negative). Never heard of the negative side of anything in the world being red.

 

[XSLeo]

You know how them Brits are, they drive on the wrong side of the road.
I think the statement "all Brit bikes are positive ground" is not exactly right. I think some of the older Brit bikes had positive grounds. But I think most modern bikes world wide are negative ground.
Leo

 

[ANLAF]

Looks like as long as I keep to earthing the connection Sparx says is earth (the red!) then the current will flow in the right direction.

There is another thread, too, about an exploding Sparx, and that was because it was accidentally wired in reverse order.

Anlaf

 

[xjwmx]

I keep to earthing the connection Sparx says is earth (the red!) then the current will flow in the right direction.

If they're literally saying "Earth the red" that isn't necessarily saying connect the red to negative. It could be they are giving instructions for a positive ground bike, in which case Earthing (syn. grounding) the red makes perfect sense.

If somebody did have it connected backward it might not necessarily cause a problem. These kinds of caps are "formed" at the factory which polarizes them. They will work in the opposite direction as well - if they don't pop! They will get polarized in the opposite direction if they survive...

but you know...frequently it's the negative that's marked on components rather than the positive. The band marked on a diode is on the side that goes to negative. But not in red!

 

[ANLAF]

xjwmx, have a quick glance at what was said in my thread "HUGH'S PMA weak spark with SPARX CAPACITOR".

The instructions I received from Sparx seemed to be for an old Brit bike, yet others wire the negative/earth/ground to the black.

Anlaf

 

[xjwmx]

^So on yours the red goes to the + side of the battery?

 

[deadchef]

So I got a Sparx off egay
It was for triumph and I assumed it would be the same as the xs650 one......
Guess what....
It exploded between my legs. I had it mounted between the carbs just below.

Scared the crap outta me
Seems that the positive is the negative side like all lucas positive ground stuff...
The bike still runs fine and it didn't take anything down with it thank goodness

was the bike running when this happened or as soon as you kicked?

 

[mrkil]

The bike had been running for about a minute. It started up fine and I was just checking the lights to make sure they where working because I was taking the bike for saftey inspection.

 

[mrkil]

So I ordered a Mallory cap i stead of the Sparx to replace it. Wired it in as marked red to positive and it works perfectly.
I let it run for 5 minutes and took it for a quick boot to the end of the street and no pop.

Now to just finish wiring the lights and I'm golden.