Honda CX 500 Forum banner

1 - 16 of 16 Posts

·
Registered
Joined
·
11 Posts
Discussion Starter #1
Howdy All,
My CDI's kill switch wire B/W is shorting to ground traced to the last connector leading into the CDI (works as advertised to the last part of the circuit). The bike was idling great, and I was just about to saddle-up on a sunny ride to the store (after bike stored in doors all winter in the USofA) when the engine quit. Quick troubleshoot——no spark on either plug, which VOMing lead to the devil kill switch.

Found a guy parting out an '82. I bought his wire harness and the twin igniter "update" to the CDI module. One big problem is the igniters or "spark units" have five wires going to each: Ground (Dg), the kill wire (B/W), one wire to each connector from their respective coils and then respectively two yellows/two blues from the pickup coil. My '78 schematic shows only a two-wire pickup coil: LB/W and O/W (which went to my now trash-pile CDI unit). I got a 50/50% chance (maybe) of hooking up either of these to one yellow and one blue wire going to either igniter (unless they both hook to same igniter? but I doubt it). But what two wires from the seven remaining? from the CDI would properly power those igniters? and complete the circuit for the remaining loner yellow and blue wires?

Has anybody tried this "mod" short of buying the new Ignitech units? I kinda fell into these salvaged parts, took this on as a good test of my electrical skills, but am jammed up right here (last thing to hook up before seeing if she'll fire off!) Thanks for all your wisdom.
 

·
Administrator
Joined
·
1,562 Posts
So, if you want to upgrade your bike to TCI ignition instead of CDI ignition, you need that 82 wiring harness as well as the right handlebar control. (Maybe the left one too, not sure). You'll want to swap the stator out as well as the mechanical advance from the 82 CX500 or any year GL500. This will give you a far more reliable ignition system... but it requires dropping the engine. If your bike runs fine right now and just has a bad kill switch, I would look on ebay for a new kill switch before I'd look at replacing the wiring harness.

Charles.
 

·
Registered
Joined
·
2,160 Posts

·
Registered
Joined
·
11 Posts
Discussion Starter #5
Thanks Charles. Kill switch on the R handlebar works fine tracing its power to the CDI. The B/W kill power won't shut off with the switch in RUN. There should be power on this wire with the switch in OFF. When switched to OFF the engine should kill, which it did/does, but I can't get the circuit to open even with the wire disconnected. Which I traced shorted always "ON" to the CDI, which then kills any spark to the plugs.

All the wiring in the '78 v '82 R handlebar controls (starter switch, kill switch, front rear brake light switch) all appear swappable-doable to the '82 wiring harness that I have wired in. I've switched a few wires around in the connectors, but everything checks out OK.

The kill switch in the '82 harness works exactly opposite of the '78 harness: Power must exist with kill switch RUN in order for the ignition to power up. In fact the B/W "kill switch" wire powers the coils and the "spark units."

I wan't sure, but, yes; probably need a '82 matching stator (I should be able to get that salvage too from this guy nearby) for optimum ignition. But I'm wondering if the thing will just run if I can properly hook up my '78 stator to the '82 pickup coil.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #6
Thanks for the schematics. And, yes, I should have called this converting to the TI ignition. With the exception that the older '78 stator/CDI might not be optimum for the '82 stator/TI, you'd think you'd get some kind of spark if you could hook up the correct wires from the "old" stator to the TI spark units.

Again, may be money/time ahead by just buying the IgniTech igniters. Do you know does this work with the TI system or just CDI?
 

·
Registered
Joined
·
2,167 Posts
Listen,
if you want a TI ignition then you need the igniters, wiring harness, coils from TI bike, right hand control, complete rear engine cover, pulsar in the rear cover, and just make sure you have the appropriate stator which a G8 would do just fine......

Otherwise its not gonna work, you cant make one stator work with a system its not designed for by plugging stuff together.....this cannot be Macgyvered
 

·
Registered
Joined
·
24,209 Posts
ignitec is a unit used to replace a stock cdi with a bad stator it will not at all help you with a ti harness in a cdi bike

the cdi ignition system si all ac based the coils fire on 150v ac

the trigger from the pulser will not tigger the ti ignitors nor is there any way of timing them

net issue you would have is the ti bike has a mechnical advance mechanism and the way you are trying to do this

you would have a motor with no timing advance and it would be a dog

you need to either convert to ti in full or revert to cdi as the factory cdi box and advance pulsers in teh back of the motor take care of advance

and a ignitec also has the advance curve built in
 

·
Registered
Joined
·
11 Posts
Discussion Starter #11
OK, thanks for all the info. Guess I got some bum ideas from the guy who sold me the parts who seemed knowledgeable and claimed this was doable...

So, here's where I'm at and what would the consensus recommendation be?: I have the '82 wire harness installed (which includes the '82 rectifier/regulator); I have the one-wire coils installed from my original '78 setup; I have the '78 stator installed; I have '78 both-handlebars controls installed. Would the Ignitech igniter after-market plug-in work in this config? or should I go back to square one and reinstall the original '78 harness and then clip-in the Ignitech system?

Obviously, easiest for me would be to keep the '82 wire harness installed and just plug-in the Ignitech, which I'll order. Only big difference I see is the newer rectifier/regulator. And of course I'd have to swap around the kill switch so that it would be open in RUN (instead of a closed circuit now in RUN). That might be as simple as the kill switch would have to be OFF to be in "RUN", which might be a good anti-theft set-up. Been kind of a bad cluster-F for me, but I've learned a lot, which is fundamentally a good thing! Thanks again.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #13
OK, I guess I'm glad I have an older CDI bike because at least there's a fix for a failed ignition system. I don't know what the TI guys do if their spark units fail.

So I guess I'll have to go backwards to go forwards. I'll R/R the harness back to my original, and order the IgniTech ignition system. So anybody else considering this cheaper potential––it's actually more expensive AND it won't work. Lesson learned. Thanks for all the brains/experience helping me out.

Stay tuned...I'll update as I head back to the future...
 

·
Registered
Joined
·
2,160 Posts
O K

I think lesson learned.

actually 5

1.what wont work

2.what will

3.most importantly gather intelligence

Before you attack

5.changing looms is more work than fun.

by the way there are millions of spare

NEC igniters out there I somehow have

4 good pairs

there are schematics convert to

automotive units
 

·
Super Moderator
Joined
·
14,720 Posts
In case you haven't figured it out by now the TI isn't an "update" of the CDI. It is a completely different system. And the part of the engine that the triggers the ignition is completely different between the 2 systems.

BTW: The reason the kill switch is opposite is that the CDI's kill switch works by shorting the output to ground (if you don't interrupt the current between the coils & ground there will be no spark) but the TI's kill switch simply turns off the power to the Igniters.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #16
Yes, finally learned the CDI and TI ignition systems for the CX500 are two totally different systems.

These CX500s are incredible bikes. I have owned mine for over 30 years (bought if for a buck a cc), and this is the first significant problem I have ever had. No way do I want to lay this puppy down now...
 
1 - 16 of 16 Posts
Top