Throttle grip wiring – The FCR is a push-pull carburetor. Its direct operational feel is very appealing.

Throttle grip wiring – The FCR is a push-pull carburetor. Its direct operational feel is very appealing.

I added wiring to the throttle grip. This is because I didn't like how the rubber at the base of the grip was moving around. The FCR is a push-pull carburetor, where the throttle directly opens the carburetor valves. In contrast, most stock carburetors are vacuum-operated, using the engine's vacuum to open and close the valves inside the carburetor. This is one of the differences between the FCR and stock carburetors.

Push-pull carburetors were developed earlier. They are characterized by a strong sense of direct control, as the valves are directly connected to the throttle via cables. While this might give the impression of being difficult to handle, it’s not really an issue. It can be somewhat tricky to manage, but nothing major.

The vacuum-operated carburetor was invented to address the challenges of handling push-pull carburetors. The throttle only controls the air passage, while the valve that delivers the air-fuel mixture opens and closes using the vacuum created by the engine. For a more detailed explanation of the differences between vacuum-operated and push-pull carburetors, I recommend doing a web search. There are experts who have provided detailed explanations with diagrams and pictures, making it easier to understand than my written explanation.

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carburetor push-pull CV difference

One of the advantages of racing carburetors is the ability to fine-tune them in great detail. This kind of topic has been discussed for decades in magazines and on the web. This time, I will also write about one of the characteristics of the FCR carburetor: its push-pull system. I will write this in a column-style format based on my own interpretation. There may be some incorrect expressions or mistakes, so I ask for your understanding in advance.

Now then, let's get started!

Are vacuum-operated carburetors difficult to tune?

They're not difficult to tune. It’s more accurate to say that push-pull carburetors are better suited for tuning. The reason you can achieve precise tuning with an FCR is that the height of the throttle valve is clearly defined. Tuning with the FCR is based on the throttle opening.

Vacuum-operated carburetors, on the other hand, use the engine’s suction force and the return force of the valve’s rubber. In other words, they automatically adjust the air-fuel ratio to some extent, but this automatic adjustment limits the ability for fine-tuning. This is because the force of the air and the rubber can vary and are not always constant. Additionally, the height of the throttle valve is not consistent.

Push-pull carburetors have a mechanism that is more compatible with precise tuning.

Since the base of the throttle grip was moving during operation, I wired it in place.

Throttle adjustment preferences vary. I prefer a stronger throttle return. While I don’t like having no throttle free play at all, I do prefer it to be minimal. Additionally, I want to be able to disassemble things easily, so I don't like fixing the throttle grip with adhesive. For these reasons, I use wiring to secure it. Although the return is slightly stronger, the grip has shifted a bit. Even with strong wiring, the grip continues to move.

The direct feel of throttle operation is one of the main attractions of the FCR.

Just because a carburetor is vacuum-operated doesn’t mean the throttle response is poor. The advantage of a vacuum-operated carburetor is its smooth, infinitely variable response. Push-pull carburetors, on the other hand, have the throttle and valve connected by cables, resulting in a more direct feel. To fully experience the acceleration and direct response that the FCR offers, you should pay attention to aspects such as throttle tension, play, and return strength. This is part of what makes the FCR interesting. Be mindful and adjust the throttle components to suit your preferences.

For FCR beginners – Purchase wiring on Amazon and practice with it.

I think everyone buys the same wiring from Amazon and uses it regularly. The only tool you need is a wiring tool, which is inexpensive and easy to purchase. You should be able to grasp the technique after about an hour of practice. The wire comes with red tape on the tip, so be sure not to throw it away; put it back after use. This way, you'll know where the tip is the next time you use it. There might be some tips for wiring.

What I want to say is:

'Practice for at least an hour.'

That’s my advice. You can manage to tighten it from the first try, but to do it neatly, you'll need around an hour of practice.

Throttle grip wiring – The FCR is a push-pull carburetor. Its direct operational feel is very appealing.【summary】

Adjusting the throttle area is an essential task for any motorcyclist. It also enhances the special feeling you have for your mortorcycle. You can easily adjust the throttle area yourself without needing to rely on a professional. By searching online, you can find methods and give it a try on your own. If you really can’t get it right, you can consult a local motorcycle enthusiast, who will surely help you out.

You only need basic tools, such as those in your mortorcycle's toolkit. Just remember that tools typically tighten clockwise. The FCR is a racing carburetor, and racing carburetors are designed to be easily adjustable. No one starts off knowing how to maintain them. Throttle adjustment is a simple task, so I encourage you to give it a try. See you again!

↓ Previous posts will open here ↓
Adjustment of Motorcycle Throttle Free Play

HONDA CBX1000 – Throttle Area Gallery

Photos of the throttle area are extracted from past posts and are featured here.