TCI ignition unit [is it possible?!]

[Nckgoheen]

sorry if there is already a thread on this topic but I was looking through the threads and ive only encountered how to wire a tci ignition unit.
my question is... Is it possible to remove this unit from the bike and still run? im pretty sure the ignition unit/box is what it is called. If not I am referring to the black sealed box fitted under the battery mount/box which holds a computer circuit board looking thing within it.

I understand it connects to the points, and both coils, and to ground. So I know it is an important piece but has anyone found a way to bypass it or have the bike properly function with out it? Ive seen custom xs400's that appear to have gotten rid of it, or just hid it very well

Any insight on this would be greatly appreciated
thank you,
Nick

 

[Scorpio1963]

.

 

[16VGTIDave]

The short answer is no.

The longer answer is that if you have a TCI ignition, you don't have points, you have Hall Effect transducers. Without the module you won't have spark. And retrofitting points is a step backwards, even on a SOHC engine.

 

[Nckgoheen]

The short answer is no.

The longer answer is that if you have a TCI ignition, you don't have points, you have Hall Effect transducers. Without the module you won't have spark. And retrofitting points is a step backwards, even on a SOHC engine.

so its actually better to have the tci ignition unit? I was just curious because due to age and its overall design it seems like one of those pieces that could easily fail or get ruined quickly so if there was an alternate unit I could run instead that would be more durable or better yet a way of not running it at all I was going to try and go that route.

thanks everyone for your replies so far! appreciate the feedback!

 

[xschris]

Your choices are a tci or points that's it.

 

[Charles]

so its actually better to have the tci ignition unit? I was just curious because due to age and its overall design it seems like one of those pieces that could easily fail or get ruined quickly so if there was an alternate unit I could run instead that would be more durable or better yet a way of not running it at all I was going to try and go that route.

thanks everyone for your replies so far! appreciate the feedback!

My bike is 31 years old and still running fine on the original TCI setup. Don't make things more complicated than they need to be. If it's working, leave it alone...unless you know what you're doing, and no offense, but it doesn't seem like you do if you can't tell the difference between a TCI and points ignition.

 

[Nckgoheen]

I don't to be honest, I that's why I asked. Just wanted to know what my options were and if there were alternatives or not. Appreciate your feedback guys and thanks for the help

 

[Scorpio1963]

I had to do this on my 360Dt ,well it did have TCI unit but I had to change stators,flywheel and convert back to points cause the electronic units were notorious for going dead.

 

[xschris]

I am pretty sure the DT360 uses a cdi NOT a tci That may be the reason you had problems with it

 

[XSLeo]

On a pints ignition power goes to the coil, from the coil to the points. Now when the points are open no power can flow. When the points close , power flows.
The points ground the ignition circuit.
Now with the points closed the power flowing through the coil builds a very strong magnetic field in the coil. Now as the points start to open the power flow stops. This lets the magnetic field collapse. This field collapse is what creates the high voltage in the secondary side of the coil that actually jumps the gap of the plugs and causes the spark.
On a Transistor Controlled Ignition or TCI the points are replaced by a transistor. The transistor is what turns the power flow through the coils. It does this with a set of pick up. The pick ups are just a winding of wire around a core The pick up is placed close to a magnet that turns with the crank or cam. As the magnet passes the pick up. a small current ids created in the pick up. This current is sent to the TCI box that amplifies this current to a usable level and uses it to turn the transistor on and off. The same as the points.
A cdi uses a large capacitor. As the engine turns a section of the alternator charges this capacitor. Once the capacitor is charged it gets a signal from the flywheel it's time and discharges this big capacitor through a coil. This high current from the cap creates a large power surge through the coil. This power surge acts like the magnetic field collapse as in the previous system and causes the coil to spark the plugs.
On the TCI often after 30 plus years the solder connections on the circuit board get weak. Often if the TCI quits working or starts acting weird just using a soldering iron and resoldering every solder joint on the board fixes them. Some times you may find parts that look burnt. If you can figure out what the part was it can be replaced.
I don't think Pamcopete is working on a replacement ignition for the XS400 but it might not hurt to ask. www.xs650yamaha.com is his XS650 ignition site. You can contact him through there.
Leo