A A A A Author Topic: Rae-San HALL TAI Ignition Module V4 Install  (Read 198 times)


Rae-San HALL TAI Ignition Module V4 Install
« Started on: 18-Aug-21, 14:37 »
I thought I should do a write up on the procedure as I “saw it” as it may be helpful to others undertaking this project.


I own a CX500 Euro which was a “barn find” from country NSW in early 2007. I purchased the bike as a “parts bike” as it was not running but after getting it home I had it running within an hour or two. Once I realised it could be a good working CX I removed the engine and installed new rings and big end bearings, unseized the Pro-Link suspension and it has since travelled around 30,00Km’s. The bike is actually a hybrid of a CX650 and CX500. The frame and forks are CX650 and the engine and rear swing arm, including final drive, are from a CX500. The bike also has the CX650 radiator and electric fan.

I decided to install the Rae-San version 4 TAI ignition module as the bike often struggles to fire up after sitting for several weeks. I realise this is a known problem with the CX engine but after having the carby’s fully cleaned and rebuilt I just had an inkling that this engine was struggling due to the nearly 40 year old electronic ignition system.

Being in Covid-19 lockdown gave me the time to remove the engine and install the Rae-San ignition and I foolishly thought I could get the job done over a couple of days. I had not taken into account that I am now around 15 years older than the last time I removed the engine from this bike and this year I will have a “significant” birthday.

Removing the engine was not a big job BUT it did take me around three hours or so and that was enough for one day!

The next day I removed the Pulsar cover and then the advance mechanism and pulsar plate. I reviewed the installation instructions for the Rae-San TAI version 4 ignition and something did not seem quite right. After contacting the manufacturer (Ray who is a member on this forum) he advised it would be better if I used the instructions for the version 3 ignition module as those instructions were more comprehensive for the CX model I owned. After downloading and reviewing the version 3 instructions I was fairly confident of what needed to be done during the install process. The version 3 instructions had good colour pictures of the various steps involved in installing the ignition module and setting it up and testing before re-installing the engine in the frame.

The rotor with integrated magnet is an interference fit and needed a light tap with a soft hammer to get it seated. Before installing the rotor use a marker to mark the leading and trailing edge of the magnet on the outer round face of the rotor (face that the bolt goes into). These marks are used in a later step of the install to set the initial spark timing. I used a drop of medium strength locktite to help secure the rotor in place as per the instructions provided.

Installation of the hall pickup plate was quite simple but getting it aligned correctly needed close attention to the instructions in the version 3 instruction manual. The kit was supplied with 2 x M5 cap head screws to secure the hall pickup plate BUT my engine required M6 (6mm) cap screws. I am fairly certain that all TAI models have M6 screws and I have given this feedback to Ray for his investigation.

At this stage the timing setup needed to be tweaked and Ray has done a good job of allowing this to be done when the engine is still out of the frame. First step was to remove the cover of the control unit. Once the cover was removed you notice a jumper block which is used to choose which advance curve you would like to run. My control unit was set to “Curve B” which is the default for a Euro engine and gives more advance than the CDI engines. I then connected the control unit to the connector on the end of the wiring from the hall pickup plate. Twelve volts was then connected to the power wire of the control unit (red wire on my control unit) and the negative was connected to the control unit case. This powered the control unit and hall pickup plate so I could fine tune the spark timing. I used my 12 volt jump pack to supply the power but you can use any convenient 12 volt power that you might have available including the bike battery if it is charged.

With the system now powered I followed the instructions to finalise the position of the hall pickup plate. This involved rotating the crankshaft while watching marks on the flywheel and checking when the LED’s in the control unit turned on and off. After a couple of minor/fine adjustments to the hall pickup plate, I was happy with the location so I then centred the hall pickup plate and tightened the screws to fix it in position. I used a drop of medium strength locktite on the screws as recommended by Ray. I marked the hall pickup plate and rear cover with marker pen in three locations so that I had a future reference point for the “final location” of the pickup plate if I ever needed to do maintenance in that area.

Once this was done it was time to install the pulsar cover and get the engine back in the frame. There was no grommet on the hall pickup plate wiring so I cut the grommet off of the old wiring and installed it on the new wiring. I also applied some gasket cement on the pulsar cover above the hall pickup plate as advised in the Honda workshop manual. I believe this is to help prevent most of the oil from dribbling down into the area the hall pickup plate is housed.

Once I had the engine back in the frame (do not ask how long it took but it was not later that day) it was time to find a suitable location to mount the control module and wire everything up.

When I contacted Ray earlier he suggested I may be able to mount the control unit in the location the TAI igniters used to be. This turned out to be a good location and the supplied cabling was just long enough to plug the pickup plate wiring into the control unit wiring. Unfortunately the control module was a little bigger than the two igniters so I needed to mount the control module on an angle with only one bolt securing it (which is plenty).

I used the igniter wiring harness connectors to gain access to a switched 12 volt supply, earth/ground, and the left and right coil trigger wires. I purchased some six pin plugs to match the wiring harness and connected the relevant wires from the plugs to the associated wires on the control module (12 volt power, left coil, right coil). I also ran an earth/ground wire from each of the 6 pin plugs to a common 6mm lug and attached this lug to the mounting bolt of the control module. This ensured that the control module case had a good connection to earth/ground which it needs to operate.

Once the electrics were all connected I turned on the ignition and tried to start the engine. The engine spun freely for two turns and then abruptly stopped. I tried again with the same result.

Having reviewed the instructions I remembered that the default programming of the control unit has the spark disabled for the first two revolutions to assist with engine cranking (no spark until engine cranking is up to a good speed). I realised the engine was stopping on the third revolution when the spark was firing which potentially meant I had the left and right coil trigger wires reversed. I swapped the coil trigger wires and hit the starter and the engine fired up OK.

When starting the bike a few days later it appeared to start much easier than when using the old ignition system and it also seemed to run more smoothly when cold. On a 50Km ride later that day the bike also seemed to have a bit more “Pep”. This may all be just in my mind but time will tell and I will update this post with my thoughts as time goes by.


Re: Rae-San HALL TAI Ignition Module V4 Install
« Reply #1 on: 19-Aug-21, 20:35 »
Very interesting write up Seagrass and quite topical for me as just last Sunday my 500EC blotted it's copybook for the first time in 40 years and 265,650 km when half way through a Historic Club run it refused to go over 4500 rpm accompanied by a stumbling miss and loud backfires through the carburettors.
It felt like ignition even though it started easily and ran normally in every gear until hitting the 4500 rev limit.
Determined to fault find through the list of ignition components as I have spares for all the bits and these were my steps,

  Spark plugs: NGK D8EA and were 25K km old so they needed a change,
  Coils:           tested as per the manual and both were OK,
  Plug leads:    Pulled out of the left plug cap with little to no resistance, hmm!
                      Both leads original with green corrosion on the ends and little grip on the plug cap     
                      New HT plug lead was bought from the local auto parts shop and fitted
  Plug Caps:    Spikes corroded and soaked in salt/vinegar solution then rinsed in bicarb soda back to         
                     clean metal
                     Resistors checked out OK at 4000 ohms
                     One cap had the spring welded in place and was replaced
                     Both caps took a lot of scraping with a small screw driver up through the tube to     
                     establish a clean, conducting surface for the springs to make resistance free contact
                     As did the resistor ends and the spark plug connector screws which lock up all the     
                     components of the plug lead. Both caps then read a good 4 to 5 k ohm resistance.

I was going to test the spark igniters but for the life of me could not make sense of the procedure set out in the manual. Do you leave the igniters connected to their wiring harness plugs to test the coloured wires with the ignition on? The book seemed to have the igniters disconnected and is the ignition coupler to be disconnected the little diode plugged into the harness near the fuel gauge connector?
Anyway that would have been too many parts tested at once so with new spark plugs, new leads, good coils and refreshed plug caps I was very happy when the bike happily took full throttle and revved right out.
I had looked up a previous post from 2011 about a 500EC having the exact same symptoms with guru Don Seedsman of the opinion it was the advance/retard mechanism the likely culprit and that would have meant an engine out or swing arm removal to replace them.
A final test will be a longer ride to get all components to working temperature so if the problem persists and defies solution a Rae San might be the answer.


Re: Rae-San HALL TAI Ignition Module V4 Install
« Reply #2 on: 19-Aug-21, 21:42 »
Couldn't be a jammed ATU not giving any advance?


Re: Rae-San HALL TAI Ignition Module V4 Install
« Reply #3 on: 25-Aug-21, 20:00 »
Thanks Seagrass, I will need to carry out this procedure on my current resto.


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