BATTERY
1. Disconnect:
• Negative lead (1)
• Positive lead (2)
• Breather hose (3)
2. Pull:
• Battery
3. Check:
• Fluid level
Incorrect — Refill.
Fluid level should be between upper (1) and lower (2) level marks.
The following is a guide to determing if a used TCI is appropriate for a given machine:
The original transistors used in our Transistor Controlled Ignition igniter boxes are Fuji made ETD41-035. They were discontinued many years ago.
Various sources dedicated to old Yamaha motorcycles such as the Vision and the Virago suggest that the MJE5742 is a drop-in replacement.
Battery
1. Checking
If the battery shows the following defects, it should be replaced.
a. The battery voltage will not rise to a specific value or no gassing occurs in any cell even after many hours of charging.
b. Sulfation of one or more cells is indicated by the plates turning white or an accumulation of material in the bottom of the cell.
ELECTRICAL
Battery
1. The fluid level should be between the upper and lower level marks. Use only distillod water if refilling is necessary.
CAUTION: Normal tap water contains minerals which are harmful to a battery; therefore, refill only with distilled water.
Circuit diagram 
A. C. Generator
1. Checking method
a. Connect D. C. voltmeter to the battery terminals.
b. Start the engine.
Circuit diagram
Lighting system tests and checks
Fuel sender unit
1. Inspection
a. Remove the sender unit from the fuel tank.
b. Use a pocket tester (with ohm x 10 scale) for this check. Connect the pocket tester leads across the green lead and the black lead of the sender unit. The meter should show the following resistance at the specified fuel level. If not replace the sender unit.