Last Updated on November 17, 2023 by Chuck Wilson
Yamaha’s premiere cart in 1979 was the G1A Model J10 Gas-powered vehicle that featured an Autolube Oil Injection System to supply oil to the engine in precise oil-to-gas ratios. This eliminated the premixing of the oil and gas and improved combustion, oil consumption, and carbon buildup. In 1980, Yamaha introduced the G1E 36 volt Electric J14 series.
The following diagrams are for ease of tracing out circuits and pinpointing points of failure in the Yamaha G1A and G1 E.
G1 Gasoline Carts
The first Generation Gas Carts had solenoids (or relays) that had all terminals on one end of the unit. These solenoids are no longer available and are replaced with a model with terminals on both ends. The replacement for the gas cart is a 12-volt model.
Retrofit for this solenoid is shown in the illustration below.
G1A,A2,A4,A5 Gas 1979-81, 1983-89
G1A3 Gas 1982
| Engine Will Not Turn Over | Battery is not charged | Test and recharge |
| Poor terminal connection | Clean and tighten | |
| Bad starter motor | Test, repair or replace | |
| Engine Turns Over, Will Not Start | Moisture on ignition wires and spark plug cap | Wipe wires and cap clean and dry |
| Faulty ignition cables | Replace any cracked or shorted cables | |
| Open or shorted primary ignition circuit | Trace primary ignition circuit and repair as necessary | |
| Faulty coil | Test and replace if necessary | |
| Dirt or water in fuel line or carburetor | Clean lines and carburetor. Replace filter | |
| Faulty fuel pump | Install new fuel pump | |
| Carburetor flooded or carburetor float setting incorrect | Adjust float level – check seats | |
| Loss of Power | Dirt or water in fuel line, carburetor or filter. | Clean lines, carburetor and replace filter |
| Incorrect ignition timing | Reset timing | |
| Dirty or incorrectly gapped spark plug | Clean plug and set gap – replace if neccessary | |
| Engine Stalls | Incorrect choke adjustment | Adjust choke |
| Idle speed set too low | Adjust idle speed on choke | |
| Incorrect carburetor float setting | Adjust float setting | |
| Faulty ignition wiring | Trace out and correct | |
| Dirty or incorrectly gapped spark | Clean plug and set gap | |
| Contaminates in fuel line or carburetor | Clean lines, carburetor and replace filter | |
| Faulty Coil | Check and replace | |
G1 Electric Carts
The first generation electric cart had solenoids (or relays) that had all terminals on one end of the unit. These solenoids are no longer available and are replaced with a model with terminals on both ends.
Below is the retrofit for replacing these with a contemporary solenoid.
G1E 1980-86
Item List
- Batteries 6x6v
- Solenoid Relay
- Speed Controller
- Resistor Coil
- Traction Motor
- Charge Receptacle
- Back Up Buzzer
- Stop Switch (at pedal)
- 10 amp Fuse
- 10 amp Fuse
The wiper arm is at full rest and making contact with Contact Terminal #1.
- Key switch – Off
- Speed Controller – At Contact #1
- Forward Solenoid – Not Energized
- Reverse Solenoid – Not Energized
- Voltage to Motor – None
- Voltage across A1 and A2 – None
- Voltage across F1 and F2 – None
- Stop Switch – In Open state
Power Flow Logic Diagram – Forward 1st Speed
First Speed -the wiper arm is making contact with Contact Terminal #1 and pedal is slightly pressed.
- Key switch – Forward
- Speed Controller – At Contact #1
- Forward Solenoid – Energized
- Reverse Solenoid – Not Energized
- Voltage to Motor – Present
- Voltage across full resistor
- Stop Switch – In closed state
Power Flow Logic Diagram – Forward 2nd Speed
Second Speed – the wiper arm is making contact with Contact Terminal #2.
- Key switch – Forward
- Speed Controller – At Contact #2
- Forward Solenoid – Energized
- Reverse Solenoid – Not Energized
- Voltage to Motor – Present
- Voltage across 4/5 of resistor
- Stop Switch – In closed state
Power Flow Logic Diagram – Reverse 2nd Speed
Second Speed Reverse – the wiper arm is making contact with Contact Terminal #2.
- Key switch – Reverse
- Speed Controller – At Contact #2
- Forward Solenoid – Not Energized
- Reverse Solenoid – Energized
- Voltage to Motor – F1 and F2 flow reversed
- Voltage across 4/5 of resistor
- Stop Switch – In closed state
- Reverse buzzer – Energized
G1E Controller Exploded View
Troubleshooting Chart
| Motor Will Not Turn | Motor terminals are loose or corroded. | Tighten or clean tereminals |
| Brushes not contacting the commutator | Adjust | |
| Lead wires faulty | Check continuity, test, repair or replace | |
| Field coil broken | Repair or replace | |
| Armature coil broken | Repair or replace | |
| Motor Turns Slowly | Terminals loose and/or corroded | Check terminals, clean and tighten |
| Accelerator arm movement restricted | Adjust linkage | |
| Leads partially broken or loose | Check for loose wire strands, replace if defective, tighten connection | |
| Bearings Overheating Power | Bearings worn or low on grease | Replace |
| Bearings not installed correctly | Adjust bearings | |
| Noisy motor operation | Mounting bolts loose | Tighten mounting bolts |
| Bearing failure | Replace | |
| Bearings dirty | Replace | |
| Bearings run out of grease | Replace | |
| Dirt or foreign material in motor case | Clean motor | |
| Motor Vibration | Armature out of round | Replace |
| Motor mounting bolts loose | Retighten | |
