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How To Fix Motorcycle Engine Pre-Detonation

 

How To Fix Motorcycle Engine Knock

Your bike can automatically detune its engine, but there’s an easy fix.

_by Eddie Hilgendorfen |May 10, 2023

Many modern motorcycles are designed to compensate for low-octane gasoline in an attempt to prevent motorcycle engine knocking. Unfortunately, the technology involved may also cause reduced performance, rough idle or lack of throttle response, making for a less than stellar ride experience. Fortunately, we can help you understand the root cause of this problem, and offer an inexpensive, quick and easy solution.

What is engine knocking?

Engine knock  or pre-detonation is caused by an improper detonation within the engine, which happens when fuel ignites outside of a timed ignition from the spark plug. In the race to improve fuel economy, modern high-performance engines have increased compression ratios, which also inherently increases the chance of pre-ignition detonation.

Octane measures gasoline performance against pre-ignition, detonation and the resulting engine knocking or pinging. The three most common octane ratings are:

  • Anti-Knock Index (AKI)
    The rating typically displayed on North American gas station pumps as the average of the fuel’s RON and MON octane ratings (R+M)/2.
  • Research Octane Number (RON)
    This rating is determined by testing fuel using a variable compression ratio under controlled conditions and is the most common industry rating worldwide. When comparing octane ratings, RON is typically higher than the AKI number, so an 87-octane AKI fuel at a typical gas station typically has a RON of 91-92. AMSOIL uses RON when conducting product validation and performance testing.
  • Motor Octane Number (MON)
    MON differs from RON testing by using a preheated fuel mixture, variable ignition timing and a higher engine speed to increase ignition stresses on the fuel. Though the tests are unrelated, MON results are typically 8 to 12 octane lower than RON.

Causes for loss of power and efficiency

Low-octane gasoline is more susceptible to uncontrolled and early ignition in the combustion chamber, so the higher the octane, the more compression the fuel can withstand before igniting. Pre-ignition robs the engine of power, can cause a noticeable knocking or pinging sound, and if left unchecked, can even cause catastrophic piston or cylinder damage.

This is why I decelerate (turning off the cruise control) when driving up or climbing steep hills and I also sometimes turn off the air conditioning. Also doing this you can see A decent increase in your fuel efficiency

High stress combined with lightweight design caused this dirt bike piston to fail. Dude was in first place so missed out on the cash prize.

Reduced performance.

Many modern motorcycle engines are equipped with a knock sensor. Pre-Detonation causes this sensor to adjust timing to compensating for low-octane gasoline. Unfortunately, adjusting the timing usually results in a noticeable decrease in performance, rough idling and lack of throttle response. When timing changes are done correctly, most riders shouldn’t even be aware that the performance has been reduced, but it’s easy to resolve this performance problem.

Boosting octane To Reduce Knock

The risk of engine knock can be reduced by:

  • retarding ignition timing
  • enriching the air-fuel ratio
  • reducing cylinder pressure or engine load
  • reducing the throttle or boost especially as you climb a hill
  • increasing the octane rating of the fuel
  • Engine work – lower compression

Therefore, the performance degradation caused by reduced engine timing can most easily be eliminated by increasing the fuel’s octane number. AMSOIL Motorcycle Octane Boost increases octane up to three numbers. On a bike that can be significant! This helps to eliminate motorcycle engine knocking and maximize power, performance and fuel efficiency. We get a LOT of feedback on this. Check out the product reviews.

 

 

 

 

Engine Detuning Kills Performance: How to Protect Your Motorcycle

Engine Knock Kills Performance: How to Protect Your Motorcycle

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Some modern motorcycles are equipped with a knock sensor that adjusts timing to compensate for low-octane gasoline and eliminate engine knock. Unfortunately, when timing is adjusted, you may experience…

  • Rough idle
  • Lack of throttle response

Many bikers don’t even know this is occurring. Understanding engine knock, also known as detonation or pre-ignition, requires an understanding of octane, which is a standard measure of gasoline performance.

The three most common octane ratings include:

  • Anti-Knock Index (AKI)
  • Research Octane Number (RON)
  • Motor Octane Number (MON)

AKI is the rating most bikers are familiar with. It’s typically displayed on gas pumps as the average of the fuel’s RON and MON. RON, however, is the most common industry rating.

 

Engine knock can cause piston damage

Gasoline’s RON is generally a few numbers higher than the AKI posted on the gas pump (e.g. 87 octane fuel, or regular pump gas, has a RON of about 91-92). The higher the octane, the more compression the fuel can withstand before igniting. Low-octane gas is susceptible to uncontrolled and early ignition in the combustion chamber. It causes a knocking or pinging sound, robs the engine of power and, left unchecked, can cause catastrophic piston damage.

Engine knock may be eliminated by using a higher-octane fuel. Alternatively, you can use a fuel additive designed to raise the fuel’s octane number.

 

Boost Octane and maximize power and efficiency

AMSOIL Motorcycle Octane Boost increases octane up to three numbers, which eliminates knock or ping and maximizes power and efficiency.

octane_graph

An easy solution for engine detuning

Motorcycle Octane Boost offers a low-cost solution to engine detuning and helps maximize bike power and performance. It offers the
added benefits of maintaining engine and fuel-system cleanliness, with active detergents that help prevent deposits for improved efficiency.


Amsoil's motorcycle Octane Boost for maximum performanceAMSOIL Octane Boost

  • Maximizes power and efficiency
  • Improves startup performance
  • Eliminates engine ping or knock

 

 

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