Charging and Ignition
The Electrical system on these old Viragos can be a bit of a nightmare. To fulfill the minimilist style I want, I need to use a lithium ion battery. Based on internet research, I've chosen an Antigravity 12-cell lithium battery. There are alternatives, but this is the commonly used battery for these large capacity, hard to start cafe racers.
Now that I've got modern battery technology, the 40 year old charging system needs some attention as well.
Regulator/Rectifier
To protect the exxy battery from variable charging current the Regulator/Rectifier has got to be replaced. The original diode equipment can fail catastrophically for a lithium battery, and the newer mosfet technology provides a much more consistent output and is much less likely to fail. Mine is a
Forseti mosfet unit from JapBikeSpares (https://www.japbikespares.com/yamaha-xv750-virago-81-83-forseti-regulator-rectifier-assembly-14501)
Stator
The stator is a pretty straightforward piece of equipment, but the insulation between the coils can break down over time, decreasing and ultimately eliminating the effectiveness of charging. Running a lithium battery completely flat can destroy it, so as a precaution I am replacing the Stator with a new one from Caltric in Canada (http://www.caltric.com/index.php/motorcycles/yamaha-xv750-h-virago-1981-stator.html)
Starter Relay/Solenoid
I've used the Revival Cycles Youtube Channel extensively to understand what I'm doing electrically. One of the things they suggest, especially when using an m.unit is to have an integrated stater relay/solenoid/main fuse (https://youtu.be/QwBX8WvcYNU). They happen to have one in their shop (coincidence?)... (https://revivalcycles.com/collections/motorcycle-relays/products/universal-starter-relay-solenoid)
Ignition Coils
These bikes do have a reputation for being hard to start (see the starter gear or 'bag of bolts' issue) so I want to make sure it is as reliable as possible. I don't strictly need to replace the ignition coils, but while rewiring the bike, I thought I'd bite the bullet... Dynatek coils seem to have a pretty good reputation, though Accel would probably be a good choice too. I chose the 3 ohm single output Dyna coils.
TCI
The last thing in the electrical circuit to talk about is the TCI. Again, this is a common failure point and due to the construction of them they are very hard to repair and buying a used one is just buying someone else's problem. Luckily, a company in the Czech Republic (ignitech.cz) make an inductive ignition to fit which is programmable and offers changes to the ignition advance depending on the rpm of the motor. It comes programmed for the bike, so I don't need to play with it to get it running, but I can...
Now that I've got modern battery technology, the 40 year old charging system needs some attention as well.
Regulator/Rectifier
To protect the exxy battery from variable charging current the Regulator/Rectifier has got to be replaced. The original diode equipment can fail catastrophically for a lithium battery, and the newer mosfet technology provides a much more consistent output and is much less likely to fail. Mine is a
Forseti mosfet unit from JapBikeSpares (https://www.japbikespares.com/yamaha-xv750-virago-81-83-forseti-regulator-rectifier-assembly-14501)
Stator
The stator is a pretty straightforward piece of equipment, but the insulation between the coils can break down over time, decreasing and ultimately eliminating the effectiveness of charging. Running a lithium battery completely flat can destroy it, so as a precaution I am replacing the Stator with a new one from Caltric in Canada (http://www.caltric.com/index.php/motorcycles/yamaha-xv750-h-virago-1981-stator.html)
Starter Relay/Solenoid
I've used the Revival Cycles Youtube Channel extensively to understand what I'm doing electrically. One of the things they suggest, especially when using an m.unit is to have an integrated stater relay/solenoid/main fuse (https://youtu.be/QwBX8WvcYNU). They happen to have one in their shop (coincidence?)... (https://revivalcycles.com/collections/motorcycle-relays/products/universal-starter-relay-solenoid)
Ignition Coils
These bikes do have a reputation for being hard to start (see the starter gear or 'bag of bolts' issue) so I want to make sure it is as reliable as possible. I don't strictly need to replace the ignition coils, but while rewiring the bike, I thought I'd bite the bullet... Dynatek coils seem to have a pretty good reputation, though Accel would probably be a good choice too. I chose the 3 ohm single output Dyna coils.
TCI
The last thing in the electrical circuit to talk about is the TCI. Again, this is a common failure point and due to the construction of them they are very hard to repair and buying a used one is just buying someone else's problem. Luckily, a company in the Czech Republic (ignitech.cz) make an inductive ignition to fit which is programmable and offers changes to the ignition advance depending on the rpm of the motor. It comes programmed for the bike, so I don't need to play with it to get it running, but I can...
