[TrialsRider]

I like electricity and speak wiring schematic but I would need to start with a wiring schematic of the original bike and the donor bike too.
I looked at the honda cbx750 rc 17 wiring and the 5 wire connector is coming from your alternator
the 4 wire connector is coming from the pulse generators to the CDI on both bikes and those might be close enough in concept to work, but I would check the service manuals for both those machines and see if the ignition coil resistance is the same. Wiring diagram implies it's the same part, so I'm optimistic it will work.

 

[TrialsRider]

I looked at everything
Wiring for the NT shows a 3 wire output from the alternator, that means it has no brushes and no exciter coil.
http://hawkworks.net/manual/images/19/wiring-diagram.gif
The diagram for the RC17 shows that it has an exciter coil in addition to the 3 phase alternator outputs. that means it has carbon commutator brushes that energize a 4th. coil which is a completely different type of alternator.
http://teamrc17.net/teamrc17.net/files/CBX-wiring.gif

Alternator feeds the battery charging system in both these motorcycles, they do that through a rectifier/regulator which is very different between the 2 motorcycles. The alternator/regulator/rectifier assembly is Not part of your CDI. Both engines have 2 pulse generator coils to control spark timing and while one engine is a twin and the other a 4 cylinder they are both fitted with a total of 4 plugs firing in pairs, the NT has 2 plugs per cylinder.

The pulse generator signals the "spark unit" which is the CDI (Capacitor Discharge Ignition) and those appear the same in both diagrams (4 wires in & 4 wires out). The 2 ignition coils have a very low internal resistance and for the CDI units to be compatible I would expect the ignition coils on both those machines to be the same or similar in power draw. If the ignition coils have the same internal resistance, they likely are interchangeable and so would be the spark units powering them.

 

[TrialsRider]

On the NT
The 3 yellow wires are your 3 uncontrolled AC outputs each out of phase to one another, on the NT the R/W(red-white) & G (green) wires coming from the rectifier/regulator is your rectified 12 VDC output. Magnets inside the alternator are permanent type so no exciter coil or brushes are required.

On the CBX
The 5 wire connector with 3 yellow wires each having AC output similar to the NT, but on the CBX the other 2 wires (white and black) are to energize the alternator exciter coil, the CBX alternator has an electro magnet instead of the permanent magnets used in the NT and the exciter coil powers an electro magnet inside the alternator.

The connectors on both 'spark units' have 4 wires in and 4 wires out, but one connector is a 6 pin connector that only uses 4 pins so that you don't connect to the wrong one by accident.

 

[TrialsRider]

CBX alternator charging circuit:
(either works now or needs service to charge your battery)

CBX Ignition system:

... there is a small error on that diagram in the way they draw or tag the 4 and 6 pin connectors

NT ignition circuit from your NT donor machine: (virtually the same)

 

[TrialsRider]

TR why do you keep talking about the charging circuit? He only asked about the CDI/ ignition circuit (which you also touched on).

Because he is using 'number of pins' to describe connections that can only relate to the charging circuit. That has little to do with the ignition circuit which is the CDI part.

 

[TrialsRider]

I don’t see where you got that. The charging circuit you posted has a 6 pin and 4 pin connector. Not a 5 pin. But I see no 5 pin connector anywhere, so I don’t know how you jumped to that conclusion.
...

Where did I get 5 pin connector from -> his first post:

Need help on wiring ... it has 4 pins adjacent to a 5 pin ...

8Ball you see no 5 pin connector anywhere? -> then you are not looking at the wires coming out of the alternator in the diagram I posted. There are 5 wires required in the alternator connector and that part is also indicated as a 6 P connector on the drawing.
If the "wiring ... it" has a 5 pin connector logically that would be connected to the alternator which requires 5 wire connections, the 'spark unit' didn't grow and extra connection, that component is faithfully shown with 4 wires in and 4 wires out on both engine spark units.

Why should the spark unit interchange:
His original engine has 2 pulse generators the donor has 2 pulse generators.
His original engine pulse generators (2) are in turn connected to 2 ignition coils that are in turn connected to a pair of spark plugs (2) that fire simultaneously. By the schematics I sourced, the donor circuit is identical (save for the notation errors in the drawing where they tagged the 6P connector as 4P and the 4P connector as 6P)
So we have the same number of spark plugs(4), firing by a 'spark unit' that is shown in both schematics to be the same. Plus I advised he research the resistance load on the ignition coils in the service manuals to make sure those are the same in both the donor and original coils. Same output parameters would imply the same power requirements from the 2 spark units. ... So ya, I think it's a pretty safe conclusion based on the schematics I sourced, and the OP's sketchy description of what is in front of him, the ignition system "spark unit" should interchange.

Lastly, Honda is not stupid, if Honda can use the same simple ignition component in more then one product line they will, why on earth would they make a spark unit model specific?

 

[TrialsRider]

Hope he appreciates us doing all his homework lol & why are you worried about a rev limiter, it's doubtful either of these 1980's carbureted machines has one. And btw this is a TCI not a CDI TCI = Transistor Controlled Ignition

 

[TrialsRider]

This is not a fuel injected motorcycle guys, it's old bone technology in a little black box. These engines are designed to run out of carburetor, there is no hi tech computer on board shutting down non-existent fuel injectors. What you see on the wiring diagram is what you get.
... I've given him the pulse generator coil resistance he should be seeing and if he doesn't then the box is not likely compatible for the CBX pulse generator coils and that ends that.

 

[TrialsRider]

... the spark unit determines the rev limit. ...

That would be a huge fail, rev limiters work by curbing the fuel supply, not by removing the ignition. Thus has it always been. Your plan to remove the spark at maximum revs under WOT would pump raw fuel into your exhaust system, nobody does that or at least not successfully, it would either melt down or explode.

... once you remove the fuel the ignition spark becomes wasted and has no consequence.

 

[TrialsRider]

Rev limiter on a carbureted engine works off centrifugal force, usually in the form of a fan and sail, to shut down the throttle via a mechanical linkage, just like on my snow scoot or lawn mower or generator or roto-tiller or snow blower. Depriving it of spark on and off at max revs would make it backfire to say the least, whats your plan for all that extra raw fuel traveling through the engine, hope it evaporates in the atmosphere or burn and explode in the exhaust ? Nobody does it that way, they stop the fuel flow. Once you stop the fuel flow stoping the spark would only serve to foul the plugs rapidly, nobody would do that even on a fuel injected engine, on fuel injection you simply don't activate a fuel injector for a cycle or two and the task is accomplished. Carburetor you rev limit by backing off the throttle, which is shutting down the fuel, it's mechanical.

 

[TrialsRider]

You guys know how to make an old car backfire? Extremely hazardous to your engine health but it's not difficult.

RC17 has a cable driven tach, not much chance the spark unit has any way to sense engine speed electronically there. If you research NT400 which was fitted with an electronic tach, you will find some reference to 'some units' (apparently not those sold in america) and those may feature an additional wire connection between the tachometer and the spark unit. (that would explain his Philippean NT400' fifth connector.) That info was gleaned off forums and not a service manual or Honda document. If anybody has a wiring diagram of a spark unit that does more then just spark, post it up so we can see how that works. Logically. if you were going to curb the revs on a motorcycle fitted with CV carbs, it would be pretty silly not to control revs through the carburetor vacuum control.

If y'all figure out what happens to all that excess fuel going out the exhaust pipe on your intermittent spark unit unicorn, post that up so we can see how that works too. Most likely, dumping raw fuel into the exhaust at top speed is not a feature that would make it past EPA, that concept might still fly in some third world country, at least right up until it catches fire.

I've never heard Toni Bou bounce his 4RT off a rev limiter so I seriously doubt mine even has a rev limiter, but I'm going riding now and see if I can find one.

 

[TrialsRider]

Period Spark Unit is an analogue device and to sense a rev limit it needs to do that mechanically or electronically. A tachometer circuit is required to control the ignition electronically but these are early 1980's spark units designed to replace breaker points ignition, there is no eprom inside, it's just a simple spark unit, there is nothing inside to programme. Only way to definitively know what is inside a sealed black box is to look at the wiring schematic for that device. We need the wiring schematics and then you will see how totally simple the circuit inside it really is.

 

[TrialsRider]

 

[TrialsRider]

You are arguing, I was trying to help him with a motorcycle problem.

 

[TrialsRider]

This looks like late 1980's early 90's electronics and you need early 1980's tech, I found links to documentation on the Honda and Oki IC chips but was unable to view the documents.
Ya, the Lifan only lights one spark plug, your bike fires 2 at same time.
lol maybe if you had 4 Lifan that might even work without cooking.
We call that a Bush fix no idea what you call it, maybe a beach fix

 

[TrialsRider]

Motorcycle scrap yards here have a good supply of Honda 4 DOHC and similar parts bikes, I take it that is not a common thing where you live. Scrap yard visit would be the way I would deal with it, sourcing a black box replacement from a similar model machine will make it so much more simple and less likely to fail.

 

[TrialsRider]

I think we are looking for a Hitachi TID14-29
if you can't source one locally I can try the nearest scrap yard here.

 

[TrialsRider]

The yard I will be picking is near Perth Ontario Canada

it's like find waldo but outside in freezing temperature

 

[TrialsRider]

@Durtysouth garage I've got the part, PM me your mailing address and I can make it happen for you.

 

[TrialsRider]

He hasn't been here for almost a week. Maybe PM him.

How difficult is it going to be for him to import the used part to the Philippine I never sent anything there before, can I just mail it and he clears it through customs or is it going to get complicated?