Timing light not working

[Guest]

Hi everyone. This site has been a true blessing. The carb gurus helped me imensly.
So I'm trying to check my timing on a 1981 gsx400. My timing light will not pick up the signal. I have connected to a separate 12v battery and still nothing. If I hook it up in my truck it works just fine. I read elsewhere it could be protected plug wires. Well mine still has stock coils and the wires are permanently connected so I can't even try a different wire. If this has been covered before I'm sorry the search function was little to no help.
Thanks for any and all information

[Steve]

Might just be your light.

The inductive (clamp-on) timing that that I use works just fine with the stock coils and wires.

Your light might not be as sensitive.

.

[Anfoman76]

That's strange. It is an inductive clamp on Snap on that I've never had issue with before. It is old but works fine on all the cars and trucks around here.

[jabcb]

Back in the 1970s when cars & bikes had points, car coils were so much better than some bikers would install car coils.
My Craftsman inductive timing light is from the 1970s works fine on bikes, but it hasn’t seen much use.


Maybe your timing light is only sensitive enough for the more powerful car/truck coils. Perhaps because of its design, or because its seen better days.

Do your auto parts stores have free loaner tools? If so, you could try their’s for free.

[OldVet66]

It would seem to me that it is probably not getting a trigger to fire the coil. You can get a holder or make one that you ground to the motor so you can physically check for a spark with the plug out of the motor. If you can't see one it's time to start looking elsewhere.

[Gorminrider]

I can't answer because I have an even older strobe that connects between plug and lead and works fine....but

I read elsewhere it could be protected plug wires

..interesting, but these aren't protected wires...they have a resistance in the cap to suppress spark noise and increase "reluctance"(?)

Idea? You MIGHT check/replace your spark plug for the test. Often these are ALSO radio suppressing. (there's an L in the number. NGK DR8ES-L? so find a DR8ES differnet brands might have a different letter for suppression U?) The L's work ok but if you put a non-suppression plug in in might make the difference...ie you might have too much suppression in the line IF you still have the oem plug caps.

But there's not much you can do on a GSX400 per timing anyways unless you start filing away at the sensor plate or something...

[mnferwerda]

I think the word is "inductance"