Motorcycle Forum banner
1 - 20 of 56 Posts

·
Registered
Joined
·
38 Posts
Discussion Starter · #1 ·
A little background on me.
Ive been riding and building bikes for over 60 years and have never run into a problem like this.
I bought a Chinese Rhino Hunter sport 250 Vtwin and I cant get a spark out of it.
I have changed all of the electrical parts except for the two coils which I will do next week.
I would like to know what is needed to set up a static DC CDIignition system away from the bike to see if I can get a spark.
The wiring harness was a rats nest so I have to rewire the bike myself.
I have tried using the sensor in the bike to trigger the spark ,no luck.
I have replaced the stator and sensor. No luck.
What can be used as the trigger in a static setup to act as the trigger sensor when I tie all the pieces together on my bench to make it spark?
 

·
Premium Member
Joined
·
6,159 Posts
Is the trigger sensor in the bike a small coil mounted next to the rotor? If so, it may not trigger unless the magnet that passes by it passes close enough to generate an adequate pulse, and may also need that pulse to occur as fast and often as it would when cranking the engine for the electronics to decide to trigger a spark. Which end of he magnet you use matters, too, so the pulse will be the proper polarity.
You would also need to confirm that the sensor is actually working; if it is a coil, you should be able to measure its resistance and, if you have an oscilloscope, quickly move a small magnet by it and monitor for a small pulse.
 

·
Registered
CB125T, EX250 commuter, Ninja 250 racebike, VF500F, CBR600RR, VFR750F
Joined
·
355 Posts
Most likely this is not CDI ignition as those went out of favour back in '80s (too short spark duration). You're probably dealing with transistor control ignition (TCI) which grounds inductive coils to fire.

1. verify you have +12v appearing on both coil terminals with key ON

2. as mentioned, scope pick-up coil signals. Will be VR- variable reluctance signal like this.

In this particular case, ECU was configured to look for trigger signal with rising slope, but pick-up coil had been wired up in reverse and trigger signal started with negative slope. So ECU was blind and never saw triggers. Swapping wires on pick-up coil fixed ignition in this case

3. Verify ECU fires coils with grounding pulses. Very short pulses, won't light up test lights. So you'll want to use solenoid light or scope to test. Voltage at coils actually drops to zero in order to fire coils.


Don't try to bench test ignition system, especially if you don't know what kind of signals/triggers and timing it uses. You won't be able to replicate trigger signals exactly same as on bike. Bench-testing typically uses signal-generators to simulate crank-triggers. Such as this combo missing-tooth signal on Ninja300 (note multiple VR triggers per crank-revolution).

And flywheel triggers that generate that signal (note missing tooth).


Many modern systems use missing-tooth signal to gather 2 different pieces of information:

1. velocity of crankshaft can be determined by timing spacing between individual triggers.
2. TDC is signaled by missing tooth

These signals allows ECU to have 3D ignition maps based on RPM x LOAD for optimum ignition under all conditions. Not just WOT like old style 2D maps based upon RPM only. Which is still better than fixed ignition that fire directly from crank triggers.

ECU can also measure acceleration of crank after each ignition-pulse due to power-stroke. If it doesn't move as fast as anticipated, ECU can flash MIL/CEL code to indicate misfire in that particular cylinder.

As mentioned, look at what crank-triggering is used on bike. Look for pick-up coil near flywheel and look at trigger-teeth pattern on flywheel. Measure impedance of pick-up coil. and verify with specs in manual. Might just be case of broken pick-up coil, improperly spaced pick-up from trigger teeth, or even broken wire between pick-up and ECU.
 

·
Registered
CB125T, EX250 commuter, Ninja 250 racebike, VF500F, CBR600RR, VFR750F
Joined
·
355 Posts
One axiom of effective troubleshooting (fast and least costly) is to not replace perfectly working parts with brand-new perfectly-working parts because nothing will change and symptoms will persist.

For example: "I have changed all of the electrical parts". Obviously these parts were not defective, but you changed them anyway? Shotgunning pile of parts is inefficient in terms of time and money because in process of replacing 100 parts, you may randomly replace the ONE part that's actually defective.

Instead, test and measure parts to come up with numbers to compare with standards in manual to determine it if part is good or bad. This is what professional dealer mechanics do to fix bikes. They don't have luxury of time to swap every single part on bike to luckily replace the ONE bad part. Nor do they have endless inventory of every part for every single bike ever made. Most important tools good mechanics have used for over 100-yrs are multimeter and vacuum gauges, now add oscilloscope.

You're probably familiar with measuring battery voltage to determine condition? Well, there's test for every single other part on bike. You're down to just coils? Then let's test them to find out if they're good or bad.

1. measure impedance of coil primary windings. Ohms=???
2. insert spark-plug into hi-ten wire.
3. ground case of plug with jumper wire
4. connect one terminal of coil primary to +12v battery terminal
5. connect jumper to other coil primary
6. repeatedly tap other end of jumper to -negative battery terminal

Do you see spark at plug???

Confirming coils are functional narrows it down to most likely issue: wiring problem.
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #5 ·
I agree with everything you say but I dont have a scope and the way the sensor coil is setup it cant be adjusted with the side case off.
I will try the coil test I have ohmed the coils and they measured out both equal
I replaced the parts due to a fact omitted that this bike sat in the desert since 2008 uncovered and the Arizona sun will destroy plastic in no time at all
 

Attachments

·
Registered
Joined
·
38 Posts
Discussion Starter · #6 ·
Thank you very much for your reply
Once people see the bike I never hear from them again
The diagrams leave a lot to be desired in trying to figure out exactly where all the wires go.
This is the same engine that is in the Yamaha V star bike but I think that the stator is a AC stator and I have a DC stator
 

Attachments

·
Registered
Joined
·
38 Posts
Discussion Starter · #8 ·
Is the trigger sensor in the bike a small coil mounted next to the rotor? If so, it may not trigger unless the magnet that passes by it passes close enough to generate an adequate pulse, and may also need that pulse to occur as fast and often as it would when cranking the engine for the electronics to decide to trigger a spark. Which end of he magnet you use matters, too, so the pulse will be the proper polarity.
You would also need to confirm that the sensor is actually working; if it is a coil, you should be able to measure its resistance and, if you have an oscilloscope, quickly move a small magnet by it and monitor for a small pulse.
I have been using my ohm meter and a magnet to to test for voltage pulse and there is a pulse.
a scope would be needed to determine the actual width and amplitude of toe sensor
I am ordering a hand held scope to further test the stator and sensor
If you look at the pictures I have posted you will see the stator and sensor are mounted in the outer case and the flywheel is mounted to the crankshaft on the engine.
when they are assembled there is no way to gap the sensor.
 

·
Premium Member
Joined
·
6,159 Posts
Wow, that is some fugly wiring! Also, you don't have the array of trigger magnets shown previously, so the timing is not so complex as described. I think I see a second magnet at about 9 o'clock, if it's not an illusion. But that wiring may be the real problem; it looks like it got tangled in the chain and a PO attempted to 'fix' it.. The diagram actually shows all you really need, from the sensor (blue/white and green), to power into and out of the igniter (CDI on the drawing). Note the side stand relay input, which will kill the ignition whenever the neutral switch is open (light off) and the stand is down. Without the rest of the diagram, I can't say if that input is ground or 12V when it is supposed to function.
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #11 ·
Wow, that is some fugly wiring! Also, you don't have the array of trigger magnets shown previously, so the timing is not so complex as described. I think I see a second magnet at about 9 o'clock, if it's not an illusion. But that wiring may be the real problem; it looks like it got tangled in the chain and a PO attempted to 'fix' it.. The diagram actually shows all you really need, from the sensor (blue/white and green), to power into and out of the igniter (CDI on the drawing). Note the side stand relay input, which will kill the ignition whenever the neutral switch is open (light off) and the stand is down. Without the rest of the diagram, I can't say if that input is ground or 12V when it is supposed to function.
This is the schematic I have been working from but I dont know if it shows the operational mode or just how it is wired such as the side stand switch is it normally open or closed to function
 

Attachments

·
Registered
CB125T, EX250 commuter, Ninja 250 racebike, VF500F, CBR600RR, VFR750F
Joined
·
355 Posts
Yeah this is bad. Don't doubt all these little splice segments along with bare wires may be at fault. I'd start with replacing all of these with uninterrupted new wire from end-to-end 1st



Also sidestand switch forms OR circuit with start/stop switch. Unusual logic there. Although might be inverted as AND condition inside ECU. Most common is sidestand switch should be connected in UP position.

Is there alarm installed? Seems integrated alarm-interface with quite few wires attached. Wonder if there's alarm-bypass connector that plugs in.
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #15 ·
The diagram does not apply directly to this bike
It is from the Yamaha and I was using it as a guide to figure out basic wiring of the CDI.
If I can get just the ignition portion to work I can wire the rest of the bike later.
I have cleaned up all of the splices and have the proper resistance on the stator, the sensor pulses a voltage on my ohm meter when I crank the engine ( I have a hand held scope on the way in a few days)
What I am concerned about is the side stand switch which I dont have on the bike and the DC output from the rectifier whether it needs to be in the circuit to produce a spark
I have a new stator and sensor and got the same results with them installed
This is leading me to think that the sensor gap is out of wack
This is why I wanted to use a stand alone setup to verify that all the parts function
Its about 102 degrees right now so i have about 1 hour for the sun to be in the right position so I can test the coils as you mentioned
 

·
Registered
CB125T, EX250 commuter, Ninja 250 racebike, VF500F, CBR600RR, VFR750F
Joined
·
355 Posts
If pickup-coil makes pulses you can measure, then let's assume they're working.

Not sure using Yamaha wiring-diagram would apply to this bike. Does every single wire colour going into CDI box match that diagram?

Sidestand switch wire should be grounded. Every single bike I've had in past 40-yrs have worked that way.

What about clutch and neutral switches?

I found this manual online, does wire-colours on TCI unit match what you have?
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #17 ·
Coil test both coils spark but one coil spark is weak and sporadic
The wire colors and not exactly the same
I will have to study the diagram to see how close it matches
the clutch and neutral switch is not in the picture yet
I can wire all of this after I get it to spark and start a new harness
Is there a test #2
 

·
Registered
CB125T, EX250 commuter, Ninja 250 racebike, VF500F, CBR600RR, VFR750F
Joined
·
355 Posts
what's impedance of primaries on ignition coils?
Did you use same plug for testing both coils?

Ok, so let's assume one coil is good. That should at least start bike, but..

here are givens:

1. crank-triggers work, we get output from pick-up coil
2. ignition coils work (at least one)

So problem is in between:

3. wiring to TCI box
4. TCI box itself, not as likely

Does TCI wiring you have match Lifan manual I linked above?
On both Yamaha and Lifan diagrams, sidestand, clutch and neutral switch are used. Connect them on your bike according to Lifan manual.
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #19 ·
Between the pos. and neg terminals it was 5.5 ohms on a 20 ohm scale both coils
On the high voltage plug wire to the pos terminal it was20.4k on the 200k scale.
Same plug swapped high voltage wire (same results) replace wire with brand new wire (same results) swapped plug boots (same results)
I have no side stand switch so will that line go to ground?
I do have the gear switch and with it connected to the meter and one lead the gnd I see it transfer when I put it into gear.
did you get the link about the scope?
I purchased a hand held scope and it should be here next week.
 
1 - 20 of 56 Posts
Top