Motorcycle Riders: You're Using the Wrong RPM

Summary

This video dives into the mechanics of engine RPM, emphasizing the benefits of running engines at higher RPMs for better airflow, traction control, and engine cleanliness. It contrasts low RPM, which can cause carbon buildup and pre-ignition, with high RPM, which prevents these issues. The speaker humorously explains how high RPM helps engines run more efficiently, reduces stress on components, and improves performance. It concludes with a discussion on pay-per-mile motorcycle insurance, promoting smarter, more cost-effective options for riders who use their bikes infrequently.

Takeaways

• 🏍️ The speaker rides a 1972 two-stroke motorcycle, describing the engine's power and airflow management.
• 🔄 Two-stroke engines require high RPMs to avoid issues like oil-fouling spark plugs and stalling under load.
• 🚗 Four-stroke engines can maintain lower RPMs but it doesn't necessarily mean it's the best option for performance.
• ⚙️ Engine RPM preferences aren't subjective; they're based on engineering principles that impact performance.
• 💻 Traction control adjusts engine power pulses to keep the crankshaft in sync with travel speed.
• 🎚️ Higher RPMs give the traction control system more opportunities to correct mistakes, making it more responsive.
• 🌡️ Riding at higher RPMs helps clean carbon deposits from the engine, preventing damage caused by carbon buildup.
• 🔥 Low RPMs can create dangerous conditions like pre-ignition or detonation, stressing engine components.
• 🔧 High RPMs reduce cylinder pressure and stress on pistons, whereas low RPMs increase stress and the risk of hotspots.
• 📉 Pay-per-mile motorcycle insurance from Voom is promoted as a more cost-effective option for riders who don’t ride year-round.

Q & A

What does the speaker mean by 'riding with enough airflow to avoid oil fouling a spark plug'?

The speaker refers to maintaining a high enough engine speed (RPM) to ensure adequate airflow through the engine, preventing the oil from fouling the spark plugs, which can happen when the engine is running too rich or not getting enough air.

Why does the speaker mention that bicycles exist in the context of engine RPM?

The speaker uses bicycles as a metaphor to emphasize the importance of proper engine management and efficiency, hinting that these principles apply universally in mechanical systems, like bicycles and engines.

What happens when the crankshaft spins faster than required, according to the speaker?

When the crankshaft spins faster than required, it leads to a 'spontaneous system rebalance,' where the engine's power output and control systems, like traction control, adjust to maintain optimal performance and prevent issues like traction loss.

How does traction control work in the scenario described by the speaker?

Traction control works by cutting power pulses when the crankshaft speed is not aligned with the bike's rate of travel. In lower gears at higher RPMs, the traction control operates faster, correcting any wheel slippage more effectively.

What is the significance of maintaining high RPMs according to the speaker?

Maintaining high RPMs helps clean the engine by blowing carbon deposits out of the exhaust, as the increased airflow prevents carbon buildup, which could harm the engine's compression ratio and performance.

What is the 'Italian tune-up' mentioned in the script?

The 'Italian tune-up' is an informal practice where running an engine at high RPM for an extended period helps to clear carbon buildup and restore performance, especially in engines that have been underused or maintained at low speeds.

What are the risks of operating an engine at low RPM, as explained by the speaker?

Operating an engine at low RPM can lead to carbon deposits, increased pressure on pistons, local hotspots, and dangerous pre-ignition or detonation, which can severely damage the engine.

Why does the speaker recommend using the full tachometer range?

The speaker recommends using the full tachometer range to prevent issues caused by low RPM operation, such as carbon buildup and low-speed pre-ignition, and to ensure the engine runs more efficiently with less stress on internal components.

What does the speaker mean by 'low-speed pre-ignition' or 'detonation'?

Low-speed pre-ignition or detonation refers to a dangerous condition where the fuel-air mixture ignites prematurely while the piston is still rising, causing uncontrolled combustion that can damage the engine.

What is the role of traction control in higher RPM scenarios?

In higher RPM scenarios, traction control reacts more quickly, making corrections faster and helping to prevent wheel slip more effectively than at lower RPMs, where it has fewer opportunities to adjust.