Are the CDI of differents XT600 compatibles?

Until 1989, CDI of the XT600 models:
34L/55W/43F/3AJ/1VJ/3UW/59X/3SW/36A/5Y1/5Y3/2KF/2NF/3TB(kickstart only),
those of XT550(electrically compatible but not the same advance curve!)/SRX600/TT600 are functionally compatibles, although connectors could be differents, wiring and colours are differents with sometimes 2 or 3 wires more:
Blue: connected to ground when neutral.
Blue/yellow: connected to ground when sidestand in place (disconnected when sidestand open)
Sky-Blue: wire to neutral lamp (2KF wiring).

Yamaha models codes

– Wiring to fit a 2KF CDI on a 55W bike:

  • neutral contact (sky blue) connected to sky blue wire
  • blue CDI wire connected to sky blue wire from tachometer
  • blue/yellow CDI wire connected to ground.

Caution, since 1990, XT are fitted out with TCI.
TCI from models 3TB(electric start)/3UW/3UX/DJ02/4PT and SZR660/TT600e
are compatibles.

What are the factory advance values?

Aprilia Pegasso 655 (1995) 10° at 2500rpm 39° at 4000rpm
Yamaha XT125 (55V/3YT) 9° à 1300rpm 29° à 6000rpm
Yamaha TDR125 17° a 1700rpm 23° a 4000rpm
Yamaha TTR125 6° a 1400rpm ?° a 4000rpm
Yamaha TZR125 (2strokes) 17° a 1500rpm 28° a 4000rpm
Yamaha RX135 (2strokes) 3° a 1500rpm 20° a 5000rpm
Yamaha XT250 7° a 1200rpm 32° a 4000rpm
12° a 1200rpm 34° a 5000rpm
Yamaha RD350LC 17° a 1200rpm et 9000rpm 27° a 3500rpm
Yamaha XT400 (5Y6) 12° à 1200tr/mn 35° à 6000tr/mn
Yamaha SR500 7° à 1100tr/mn 26,5° à 6000tr/mn
Yamaha XT550 (5Y3) 12° à 1200tr/mn 35° à 6000tr/mn
Yamaha XT600 (34L 43F) 12° à 1200tr/mn 36° à 4500tr/mn
Yamaha XT600 (3TB) 12° at 1200 to 2700tr/mn 28° at 6000tr/mn
XT660 (3YF 4BW)
12° at 1300rpm 38° at 6500rpm
Yamaha YP250 10° at 1500tr/mn 32° at 5000tr/mn
Honda NSR F 125 – 1987/1998 24.3° at 3000rpm
Honda NX 250 – 1989 8° at 3000rpm 30° at 4500rpm
Honda CBR 400 RR – 1988/1995 18° at idle 20° J-K models(?)
32° L,N,R models at 4500rpm
Honda CBR 600 F – 1989/1990 15° at 1200rpm
SW type 5° at 1400 rpm
42° at 5500rpm
Honda XLV 600 H to T -1987/1995 10° at idle 30° at 4500rpm
Honda XLV 600 V to X -1997/1999 10° at idle 30° at 5000rpm
Honda XLV1000 Varadero 10° at 1200tr/mn 45° at 4500tr/mn
Honda VFC750 10° at 1200tr/mn 38° at 5500tr/mn
Honda XR500R 6° at 1300rpm 31° at 4000rpm
Honda XR650R 6° at 1300rpm 31° at 3500rpm
39° at 4000rpm
Honda XR400 8° at 1900tr/mn 26-30° at 4300tr/mn
Honda XR250 8° at 1900tr/mn 26-30° at 4300tr/mn
Honda MB5 (1982) 19° +or-3
> 3000tr/mn
10° +or-5
> 7000tr/mn
Suzuki DR200 SE 7° at 1950tr/mn 38° at 4400tr/mn
Suzuki DR350 5° < 2300tr/mn 30° > 4300tr/mn (max 10500)
Suzuki DR600 0° < 2200tr/mn 30° > 4300tr/mn
Suzuki DR650 0° < 2300tr/mn 30° > 4500tr/mn
5° < 2000tr/mn 28° > 4300tr/mn

Please, give me your values to prolong the list…

What if my pickup have only one output?

You can use the PIC CDI by connecting only the entry 36°.
The XT600 uses the second pickup at 12° for a better starting, but it is not essential.
Ignitions with one sensor use the negative shape from the pickup pulse at kickstart and idle.
The PIC CDI does not use this negative shape so kickstarting will be thus harder.




I own a YaSuHonKa SX275R, will it works on my bike?

It impossible for me to answer, because you ask me to know the characteristics of YOUR motorbike!
As I cannot know electrical characteristics of thousands of models (that change every year), you must do this job of gathering information. First, carefully read the technical review!

You should be able to answer those questions:

  • How many strokes? (2 or 4)
  • How many cylinders?
  • How many ignition coil?
  • What is the ignition type?
    • Is it a TCI? (ignition coil connected to +12vdc battery)
    • Or is it a AC-CDI? (alternator provides 200Vac.)
    • Or is it a DC-CDI? (Convert the 12Vdc battery into 200Vac)
    • Or is it a MAGNETO?
  • Pickup
  • What is the ignition timing curve?




Does this CDI works on a twin?

It depend whether or not the Twin use a wasted spark!
On BMW twins, it works!

How to clean up the CDI?

The genuine PCB is embedded in a kind of resin that prevent vibrations, moisture… and reverse engineering!
To remove this mud: use Dimethylsulfoxid (C2H5OS) und Aceton (C3H6O).


Will I gain get extra power?

No. Yamaha’s engineers have the technological to get the maximum of power of their engine. If they were able to get 50 reliable HP,they would have done it… but you can modify the distribution of the power. (Ex: more advance = more torque at a particular rating) or remove the rev limiter.
Concretely, to tune the advance curve according to the engine/exhaust/carburation/air filter and to get same extra HP, it is necessary to compare the result from each curve with a power dynamometer.

TCI versus CDI

“TCI collapses an already charged coil by disconnecting it (TCI switches off briefly). These systems generally use a higher resistance
type coil and are known as an “induction” or “Kettering” ignition systems.

CDI sends a brief high (+200volts) voltage pulse to an uncharged coil which act like a transformer and multiplies it even higher.
The step up is normally around 100:1. These systems tend to use low resistance or “racing” oils.”
TCI is Not CDI


TCI and power transistor

The TCI of SR125 is fitted with a 2SD1071
(NPN Darl 6A/450V/40W/TO220 = BU806)

4 cylinders

My CDI are for single cylinder: ONE pickup give the trigger signal, the cdi calculate the delay, and finally a high tension is send to ONE sparkplug coil

A 4 cylinders WITH a DELCO work the same: in this case, there is only ONE coil and the distributor connect the high voltage to each sparkplug, one after the other. The distribution is mechanical.
The CDI only see ONE coil, like a single cylinder (one pickup => one spark)

On new vehicles, there are 4 coils, one coil for each sparkplug, the distribution is no more mechanical but electronically driven meaning the CDI must provide 4 sparks (with good timing)
In this case, my CDI are not compatibles.

How to test the ignition system?

Always unplug the component before measuring its resistance!

Models with CDI

Ignition coil (Primary winding resistance)  

ground – orange
0,8 ohm (90uH)
to 2 ohm (125uH)

Ignition coil (Secondary)

Orange – spark plug
17k ohm

Charge coil resistance (HV)

Red – brown
200 ohm or 122ohm +/-10 ohm

batterie charging coil (LV)

white – white
0,23-0,38 ohm

Pulser coil resistance

green – white/red
90-130 ohm

green – white/green
90-130 ohm

white/red – white/green  
180-260 ohm

Models with TCI

Ignition coil (Primary)

ground – orange
3,4 – 4,6 ohm

Ignition coil (Secondary)       

Orange – spark plug    
10,4 – 15,6 kohm

Pulser coil resistance

184 to 276 ohm

SR 500 Models CDI

Ignition coil (Primary winding
0,98 ohm

Ignition coil (Secondary)
12 kohm

Charge coil resistance (HV)
200 ohm

Battery Charging coil resistance (LV)
0,8 ohm

Pulser coil resistance
16 ohm
87 ohm

XT350 Models CDI

Ignition coil (Primary winding resistance)  
0,79 ohm

Ignition coil (Secondary winding

Charge coil resistance (HV)
444 ohm

Battery Charging coil resistance (LV)
0.46 ohm

Pulser coil resistance
221 ohm

XT225 Models CDI

Ignition coil (Primary winding
0,56-0,84 ohm

Ignition coil (Secondary)

Charge coil resistance (HV)
584-876 ohm

Battery Charging coil resistance (LV)
0.48-0.72 ohm

Pulser coil resistance
656-984 ohm

XT125 Models CDI

Ignition coil (Primary winding resistance)  
1.6 ohm

Ignition coil (Secondary)
6.6 Kohm

Charge coil resistance (HV)

Battery Charging coil resistance (LV)
4.5 ohm

Pulser coil resistance
265 ohm

TZR125 – TDR125 Models CDI

Ignition coil (Primary winding
0.6 – 0.8 ohm

Ignition coil (Secondary)
5.7 – 8.5 Kohm

Charge coil resistance (HV)
496 – 744 ohm W/R-W/Gr

Battery Charging coil resistance (LV)
0.6 – 0.9 ohm

Pulser coil resistance
280 – 420 ohm W/R-W/Be


How to control a stator?

  1. Check out the resistance of the wiring that must be between 0.3 ohms to 2 ohms with no continuity to ground.


  • Look at the output AC voltage with a analog multimeter instead of a numeric one.
    It’ll be more accurate and it’ll be easier to estimate how much is the peak voltage.


  • Kick start the engine, you will get around 20Vac. The faster you kick, the higher tension you get.
  • If the engine is idling, you will get around 50Vac until 150Vac at 5000RPM


How to control a ignition coil (CDI type) and spark plug?

Load a 1uF or 2.2uF condensator on the main supply (220Vac) througt a diode, then connect the loaded condensator to the primary of the coil. A spark appears to the spark plug.

: be carreful because of the main power.


How to control a CDI?

You can control if the CDI provide sparks, you can also control the advance with a oscilloscope (first channel on pin 5, second on pin 7) by measuring the delay between input pulse and output spark.
If the delay is always the same at high and low RPM: the advance is out of order!

1,2: High tension supplied by 2 small transformers 220v/9v,
connected together by their SECONDARY, to produce a isolated tension
for your security.
3: Input of the 12° sensor (unconnected).
4: Common of the sensors (connect to generator ground).
5: Input of the 36° sensor (connect to generator output).
6: ground (connect to ignition coil ground AND sparkplug ground)
7: Output to the spark coil (connect to ignition coil).

The Low Frequency Generator simulate the signal of the pickups. One
can make change the frequency (16Hz to 116Hz equal 1000rpm to 7000rpm),
the tension, the shape of wave…
In this conditions, with a condensator of 1uF, the spark length in millimeters equal High_voltage divide by 13

ie: 260volts / 13 = 20mm spark length


How to extract the advance curve?

You will need:
– to know the exact position of the pickup.
– a working genuine CDI
– a oscilloscope (or a PC with sound card + oscilloscope software can do the job…)

  1. Measure the Delay (between pickup and spark) and Period (duration between 2 pickup pulses) values at differents RPM:


  • Than use this excel sheet to convert your values to a rough advance curve.
    Accuracy depend on how many measures you’ve done, and how precise there are…