neons

bikenut · World Chat Champion Joined: 21 Nov 2011 Karma :

2 neon plug caps plumed in ( for ign testing/comparison ) would be the ideal, as the neon "flash" can be compared side for side, cylinder for cylinder, individual ign system to individual system, one for each cylinder., in cranking and running conditions, even on a road test.

The only common factor for each ign system ( apart from earths ) is the Y junction of battery voltage just before the coils., and the bike wiring thru the kill and ign switch before the coils.

So, do both coils get battery voltage when the ign is switched on. Check this with both sets of points disconnected from the coils.

back in abit.....
____________________
nuts about bikes

Evil Hans · World Chat Champion Joined: 08 Nov 2015 Karma :

What?
____________________
Triumph Sprint ST 1050. And it's Red.

weasley · World Chat Champion Joined: 16 Oct 2010 Karma :

I'ma guess this was meant to be a reply to a "bike won't start" thread somewhere.
____________________
~~Yamaha XJ600 | Yamaha YZF600R Thundercat | KTM 990 SMT~~ | BMW F900XR TE

bikenut · World Chat Champion Joined: 21 Nov 2011 Karma :

These are red plastic spark plug caps that flash when ht goes thru them. They are relatively in expensive and a good indicator of ht being present, its strength and if the ign system is "mis firing" at any point.they are useful and can prevent "hair being pulled out" or dizzyness after you have been going round in circles wondering if the bike etc has a possible fuel fault, or ign fault.

I know I am not the only person that knows about them or uses them. I have found them very useful for the past 20 years or so.

The only problem with them is the nipple has to be screwed onto the plug, so the plug end of the cap will fit the plug, and, make an adapter so the fixed nipple on the ht lead end of the neon plug cap can be made to fit the non nipple type fitting of the plug cap on the bike etc.. They are an in line neon plug cap which shows ht.
____________________
nuts about bikes

Evil Hans · World Chat Champion Joined: 08 Nov 2015 Karma :

WD Forte · World Chat Champion Joined: 17 Jun 2010 Karma :

I'd just put me scope on it.
Fannying about with neons tells you little other than it's getting a voltage higher than the turn on voltage of the neons
That's about 90V IIRC but its a tiny voltage in comparison to the voltage of a healthy spark.

Scope it
____________________
bikers smell of wee

bikenut · World Chat Champion Joined: 21 Nov 2011 Karma :

yeh but how much is a scope?

These neons are cheap and give a good indication, well worth the money.
____________________
nuts about bikes

Ste · Not Work Safe Joined: 01 Sep 2002 Karma :