How to repair the stock igniter by FastFerret

Often a common problem occurs with the bike suddenly starts running on two (or none) cylinders. The cause is likely to be a failed power transistor in the IC Igniter. As scarce as virgins in a maternity ward, these little bastards can be repaired by the brave and foolhardy….Not sure which category I fall into but here is the procedure.

Make sure that the problem is the IC Igniter before attempting this because if you stuff it up you will be in dire straights.

First you need to remove all screws and crack open the seal around the casing.

   

Use a Junior hacksaw with a wood blade in it and cut slowly and levelly.

This final procedure of cutting the casing with a junior hacksaw should be done with care and patience. When cutting into the case do not go deeper than a blade depth or you risk cutting into components. When you have finished cutting, the box will not fall apart, you need to grip it in a vice around the plug side and persuade the larger case to come away. Don’t be scared, you will have to seal the unit up afterwards with RTV silicone sealer when you are finished anyway. This will reveal the board and the suspect power transistors (shown by the screwdriver pointing device…Kawasaki special tool- so is my Grandma!).

   

These trannies allow the 12-14VDC power to be sent to the coils to get them sparking. Obviously due to engine RPM, they have to switch bloody fast and when you consider that the average life of an electronic component running constantly is deemed at 5 years maximum, they are going to pack up sooner or later. But they are not easily sourced unless you know the specs. And can get equivalents. I did this and ended up getting four of them from ‘Farnell In One’ in Leeds for £1.75 each. I used DARLINGTON TD-2 MJE5742 transistors, Farnell part number: 233-1070.

That was the easy part, now the fun begins – changing them out.

Remove the screws from the top of the trannies and the white insulators from the back of the trannies and then turn the board over and remove the layer of silicone that is on the trannie leg solder points. Be careful not to damage the tracks on the PCB, they will already show signs of lifting due to age, I just used the small point of the soldering Iron to get it to lift away and immediately used a solder sucker to remove the old solder. De-solder and remove the old trannies and fit the new ones being careful to bend the legs to suit the holes in the PCB and the aluminium plate that acts as a heatsink for the trannies.

   

Refit the plastic case cover, the metal backplate and all the screws. Fill the sawn gaps with plenty of RTV silicone sealer (RVT is the type specifically used for electronics as it is not corrosive and will not damage the PCB or components).

   

Allow the RTV to set and then bind it all up closed with Insulating tape to give it a bit of strength and tidy the job up.

Just in case you have overlooked something I suggest getting someone more intelligent to check your work, I always rely on my Dad to this.

 

My Dad.

I hope this helps you guys to keep your bikes on the road a lot longer.

FastFerret.