How to Stop a Motorcycle from Idling Too Low or Too High?

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If you are an experienced motorcycle rider, then you might already know what idling is. But for the new motorcyclist, this article will guide you regarding motorcycle idling and how to stop a motorcycle from idling too low or too high? The best idle speed really depends on the type of engine and air to fuel ratio. Most motorcycles come with a physical user manual on which you can find the optimum idle speed for your bike.

Thus we can say that the best thing you can do to figure out what idle speed is best for your bike, is to search in the user manual. In case you don’t have a physical copy, you can also google it and find out the best idle speed for your bike digitally.

The risk you might face regarding the idle speed of your motorcycle is it might become too low or too high. Too low idle speed can cause low oil pressure and is a real risk. If you aren’t going to set your idle to the factory level then you should always aim for high idle speed over lower. The following information will help you in multiple ways related to how to stop a motorcycle from idling too high or too low, so keep reading!

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What is Motorcycle Idling?

First of all the thing, you need to know is what is motorcycle idling and why it is happening to your bike?

What is dirt bike Idling? “Idling is the engine condition where the engine is running but not touching the throttle grip which means that your motorcycle engine is running at idle speed.  When you start it up in the morning, or when you are stopping at a red light and the engine is kept running. This is known as Motorcycle idling. Mostly the idle speed of any motorcycle is decided by its manufacturer and later on can be changed and modified by its owner using the owner’s manual.”

Most of the time, the idle level of any motorcycle decided by its manufacturer does not change from its standard-setting. If it does i.e. if your bike is idling high or low then this indicates that your bike may have something wrong with it. Here you will get to know about these idling issues and how to solve them.

How to Set the Idle?

If your motorcycle is idling (high or low), then there are various ways to set that. Some of these methods are discussed below;

Stop Screw – you can set the idle with a simple stop screw. Since most of the older motorcycles use carbonators to mix the air and fuel. Such motorcycles, it starts idling, can be set with a simple procedure using a stop screw. This screw prevents the throttle valves from closing completely, allowing fuel to consistently flow into the motor when you are off of the throttle.

By just simply turning the screw in or out you can adjust the idle easily. This stop screw is usually located on the carburetor near the choke of motorcycles. This same screw system is used on the first generation of fuel-injected motorcycle engines.

Engine Control Unit – While most old motorcycles have a stop screw that prevents them from idling. But most new models have new fuel injection systems mostly known as ECU (Engine Control Unit). This new system helps you to control the idle level of your motorcycles.

But if your bike has an ECU (Engine Unit Control) then you might be in a bigger problem as you cannot adjust the idle easily. If your bike has started idling poorly with an ECU then this points to a larger problem that cannot be solved by simply adjusting your idle with a stop screw. With such a system, it is usually recommended that you should take your bike to a shop and have it tuned by a professional. It does not mean that your bike is not ruined, it just means that you need a professional hand to set the idle of your bike.

Motorcycle Idle Too Low

If your bike has been warmed up and is idling lower than the recommended level from the manufacturer, you probably have the following issues with your motorcycle;

  1.  The engine will stall easily or may not stay running without throttle being added. You will also experience stalling during take offs.
  2. The oil pressure in the engine will be very low

Causes of Motorcycle Idle Too Low

Some of the potential causes of the above-mentioned problems are given below:

  • Idle Screw – if your idle screw isn’t set properly or the ECU isn’t setup correctly. Then this might be the reason behind your motorcycle idling too low. If you are an experienced biker then this is usually the first thing you would check.
  • Too Lean Air to Fuel Ratio – Mostlystock bikes usually run slightly lean so if you do any modifications such as change the exhaust or air filter. This could result in more air flow than the stock parts and cause the motorcycle to run too lean. And thus ultimately cause your bike idle too low. 
  •  Valves – the valves might have too tight of a clearance.
  • Throttle Valves – Throttle valves of your bike are probably not synced properly.
  • (TPS) Throttle Position Sensor – TPS is required to be adjusted properly if not it may cause the idling of your bike too low.  
  • Charcoal Canister – the fuel tank i.e. the Charcoal Canister might be clogged by dirt or old fuel and isn’t allowing enough fuel to the carburetor which may result in the idling of motorcycles too low.

Motorcycle Idle Too High

Though if your motorcycle idle is a little high, it is not as dangerous for your bike as if it would be too low but it is not optimal either. However, if your bike is revving out, you should shut it off and attempt to resolve the issue or you could blow up the motor. 

Problems resulting from idling too high!

When your idle is high these are usually the problems you come across:

  • Louder than usual noise from the motor winding up to higher RPM.
  • You may hear a loud grind sound when you put the bike into gear because the RPM are too high even when you are off the throttle.

Causes of Motorcycle Idling Too High!

Some of the probable causes of your high RPM are as follows;

  • Idle Screw – the idle screw might not set properly or the ECU isn’t setup correctly.
  • Oil Temperature – Your Oil Temperature Sensor or Water Temperature Sensor might have gone bad.
  • Throttle Valve – Your throttle valves might not be synced properly.
  • (TPS) Throttle Position Sensor – it might be possible that you TPS is not adjusted properly.
  • Throttle Cable – one of the cause might be that your Throttle Cable is jammed and will not allow the valves to close.
  • Cold Start Lever Cable – your cold start lever cable might be jammed and the valves cannot close.

Final Verdict

If you haven’t noticed most of the problems causing high or low idle are the same for both issues. And these problems can either be easily solved by you using the above-mentioned methods or you should take your bike to the professionals.

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