Every motorcycle has either a carburetor or a throttle body. Both of these have many components, some are common to both and some are unique to each one.
To help clear up some confusion let’s look at these 14 questions
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What is the difference between a choke and an enrichener on a motorcycle?
A choke on a motorcycle is usually a movable plate that covers the back of a carburetor to “choke” off incoming air to the engine.
An enrichener on a motorcycle is a piston-covered passageway that when moved adds fuel to the engine, therefore “enrichening” the air with fuel before entering the engine.
The difference between the 2 comes down to how each one increases fuel to the engine, the choke cuts off the amount of air coming in, and the enrichener simply adds more fuel to the current process.
What is carburetor synchronization on a motorcycle?
Carburetor synchronization on a motorcycle is the timing of the carburetor slides or plates so that they open all at the same time when the throttle is pulled.
Some carburetors can be synchronized by hand, but the preferred method is using a vacuum gauge.
Carburetors that are out of synchronization with each other can cause symptoms such as, but certainly not limited to, backfiring, throttle hesitation, and poor performance.
What is a carburetor slide on a motorcycle?
There are multiple variations of carburetor slides on a motorcycle but for simplicity, I have broken it down into 2 main types CV and non-CV.
Non-CV carburetor slide
A carburetor slide on a motorcycle equipped with a non-CV (continuous vacuum) carburetor is a metal piece attached directly to the throttle cable on the top and a needle on the bottom that controls the amount of fuel entering the engine.
It does this by sliding in concert with the throttle cable lifting the needle to add more fuel while simultaneously letting in more air from the airbox.
CV carburetor slide
A carburetor slide on a motorcycle equipped with a CV throttle is similar to a non-CV type except it is not attached directly to the throttle cable.
Instead, the slide is sealed off on the top end and connected to the vacuum of the crankcase via the valve cover.
With CV carburetors, the throttle cable is attached to a throttle plate inside the carburetor. When this plate is opened the crankcase volume increases allowing the slide to open.
What is a throttle plate on a motorcycle?
A throttle plate on a motorcycle refers to motorcycles equipped with a throttle body or a CV carburetor.
They are attached to the throttle via a cable or electronically and control the amount of air available to the engine. These can look very similar to a choke plate and operate in the same fashion.
Can carburetors be cleaned without syncing on a motorcycle?
Yes, you can clean your carburetors on your motorcycle without requiring synchronization if you are careful not to disturb any of the linkages that are associated with the synchronization.
However most of the time this is not possible, meaning you most likely will need a carburetor synchronization after cleaning the carburetors on your motorcycle.
What is throttle body synchronization on a motorcycle?
Throttle body synchronization on a motorcycle is the timing of the throttle plates so that they open all at the same time when the throttle is pulled.
The preferred method is using a vacuum gauge however, a visual inspection can tell you if the plates are in need of synchronization.
Throttle bodies that are out of synchronization with each other can cause symptoms such as, but certainly not limited to, backfiring, throttle hesitation, and poor performance.
What is a motorcycle throttle body cleaning?
Throttle body cleaning on a motorcycle is the cleaning of the portion of the motorcycle that delivers air to the engine.
This includes, but is not limited to, venturi cleaning, freeing buildup on the throttle plates, and clearing out passageways connected to it.
Common ways to do this are by hand with solvent, a chemical bath, or ultrasonic cleaning.
Should I remove the throttle body from my motorcycle when cleaning it?
Yes, a throttle body should be removed from the motorcycle when cleaning. This avoids dirt and debris from entering the airbox, valves, or engine.
It also allows easier access to the throttle plate and passages inside. In most cases, a throttle body can be cleaned with a little solvent and compressed air.
How long do you leave the choke on when warming a motorcycle?
This depends on a few factors for example the type of motorcycle, elevation, purpose, temperature, and where you are riding. Given the number of variables involved, the time needed is anywhere from 30 seconds to 5 minutes.
I know you came here looking for a real answer but all I can really offer is a trick that I use.
30-second warmup calculation
I call this my 30-second warmup calculation, basically, for every stumbling block, I add 30 seconds to the warm-up time.
For example, start with your first 30 seconds, then add 30 more per cylinder. Does the motorcycle have high mileage? Add another 30 seconds. Is it cold outside? Yes tack on 30 more seconds, I think you get the idea here.
When doing this also consider the sound of the engine. If the engine is racing, adjust it accordingly, don’t let an engine rev too high before it is warm.
In the same respect if you adjust the idle down and the engine wants to die, readjust back to where it was before and wait another 30 seconds before adjusting again.
Will leaving the choke open flood the engine on a motorcycle?
Leaving the choke open on a motorcycle while riding or when not riding won’t flood the engine. It will run very rich and if left long enough, will eventually cause damage.
I do see how this can be confusing because the choke does richen the air-fuel mixture (more gas per air) but it does this by closing off the airflow to the engine.
This means the engine doesn’t receive more fuel which is why it won’t flood the engine but it may foul the spark plug.
What happens if you leave the choke on overnight on a motorcycle?
Absolutely nothing will happen if you leave the choke on overnight on a motorcycle. This is because a choke stops air from coming into the engine, it does not add fuel so leaving it on overnight will have no effect.
Truth be told, even forgetting to turn it off when riding won’t hurt in the short term as long as it isn’t on for prolonged periods.
How long do you leave the enrichener on when warming a motorcycle?
You leave an enrichener on for 30 to 60 seconds when warming up a fuel-injected motorcycle however on a carbureted motorcycle the time can vary anywhere from 30 seconds to 5 minutes.
This is due to the same factors as the choke such as type of motorcycle, temperature, and age. Refer to the 30-second warmup calculation above for assistance in determining how long you leave the enrichener on when warming up a carbureted motorcycle.
Will leaving the enrichener open flood the engine on a motorcycle?
Leaving the enrichener open on a motorcycle while riding or when not riding won’t flood the engine but over time can cause damage.
The engine will run rich because the enrichener adds more fuel to the engine but this amount isn’t significant to flood the engine.
It may cause other problems such as carbon build-up and even foul spark plugs.
What happens if you leave the enrichener on overnight on a motorcycle?
Nothing will happen to a motorcycle if you leave the enrichener on overnight. The enrichener does add fuel to the engine but not when the motorcycle is not in operation.
Final thoughts
Motorcycle carburetor and throttle body components can be confusing but they don’t have to be now that you are armed with these 14 answers.