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Ignition Contact Set for the 1928-1929 Yellow Cab Model O-6

Keep your classic cab's engine firing properly with a reliable new ignition contact set.

3 minutes to read 1928-1929 Yellow Cab Model O-6
Difficulty
2/5
Est. Time
1 hrs
DIY Doable?
✅ Yes
Shop Labor
$90-$180
⚠️ Drivable, but... — You can drive, but stalling, misfiring, and a no-start condition are likely and can become a safety issue.
Key Takeaways
  • The ignition contact set (points) is a critical wear item in the 1928-1929 Yellow Cab's ignition system.
  • Symptoms of failure include hard starting, rough running, stalling, and loss of power.
  • Standard Ignition is a reliable aftermarket brand for this part, as original parts are unavailable.
  • Always replace the condenser at the same time as the points to ensure longevity.
  • Properly setting the point gap with a feeler gauge is essential for engine performance.
The ignition contact set, often called "points," is a critical switch inside your Yellow Cab's distributor. As the distributor shaft spins, a small cam pushes the points open and closed. This action interrupts the electrical current flowing to the ignition coil, causing the coil to generate a high-voltage spark. This spark is then sent to the correct spark plug, igniting the fuel and air mixture to make the engine run. This mechanical system was the standard for vehicles like the Model O-6 before modern electronic ignitions.

Signs of a Failing Ignition Contact Set

The ignition points in your 1928-1929 Yellow Cab Model O-6 are a wear-and-tear item. The constant opening and closing, along with the electrical current, causes the contact surfaces to pit and burn over time. The small rubbing block that rides on the distributor cam also wears down. When the points fail, your engine's performance will suffer. You will notice clear signs that it's time for a replacement.

Common Symptoms:

  • Difficulty Starting: This is the most common sign. Worn or misaligned points can't create the clean electrical break needed for a strong spark, making the engine hard or impossible to start.
  • Engine Misfires and Rough Running: Dirty or pitted points lead to an inconsistent spark. This can cause a cylinder to misfire, resulting in a shaky idle, stuttering during acceleration, and a general lack of smoothness.
  • Stalling: An engine that stalls, especially at idle or when coming to a stop, is a critical symptom. At low RPMs, a weak spark from bad points can cause the engine to die completely.
  • Reduced Power: If your cab feels sluggish or hesitates when you press the accelerator, it could be due to a weak or poorly timed spark from failing points.

Choosing the Right Aftermarket Part

For a vintage vehicle like the Yellow Cab Model O-6, finding original "OEM" parts is not practical. The market is served by aftermarket manufacturers who produce new parts based on original specifications. For the ignition contact set, Standard Ignition is a widely available and trusted brand. For decades, Standard Motor Products has been a major manufacturer of ignition components for American vehicles. Owners of classic cars often rely on quality aftermarket brands like Standard for reliable operation. Given the limited availability of parts for this specific vehicle, a new set from a reputable brand like Standard Ignition is the best choice for a dependable repair.

Cost of New Ignition Contact Set (1928-1929 Yellow Cab Model O-6)

Part Type Price Range
New Aftermarket (Standard Ignition) $21.44
Shop Labor $90 - $180

Prices are estimates and may vary based on location and supplier. Original OEM parts are generally not available for this vehicle.

Frequently Asked Questions (FAQ)

How often should I replace the ignition points?

For a vehicle of this era, ignition points were a regular maintenance item. They should be inspected at every tune-up. A properly set of points can last for 10,000 miles or more, but for a classic vehicle that is driven less frequently, it's good practice to check them annually. If the contact surfaces are pitted or the rubbing block is worn, they should be replaced.

What does it mean to "set the gap" on the points?

Setting the gap is the most critical part of the installation. The "gap" is the small distance between the contacts when the points are fully opened by the distributor cam. This gap is measured with a feeler gauge and must be set to the correct specification for your engine. An incorrect gap will affect the engine's timing and performance. For a 4-cylinder engine of this era, a typical starting point for the gap is around 0.014 inches.

Do I need to replace the condenser at the same time?

Yes, it is highly recommended to replace the condenser whenever you replace the ignition points. The condenser absorbs excess electricity to prevent the points from arcing and burning out too quickly. A failing condenser can cause new points to fail prematurely. They are typically sold together as a set.

Can I replace the ignition contact set myself?

Yes, this is a job that is feasible for a DIY mechanic who is familiar with vintage ignition systems. The process involves removing the distributor cap and rotor, unscrewing the old points and condenser, installing the new ones, and setting the gap correctly with a feeler gauge. It requires basic hand tools, a feeler gauge, and a bit of patience.

Technical Specifications

The Yellow Cab Model O-6 used a Hercules Model OOC 4-cylinder engine. The ignition system is a conventional distributor with a mechanical contact set (points) and condenser.

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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.

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