1. Introduction
Thank you for choosing the NIBBI Universal Handlebars and Throttle Grips. This product is designed to provide precise throttle control and enhanced riding experience for a variety of vehicles including motorcycles, pit bikes, bicycles, and ATVs. Please read this manual carefully before installation and use to ensure correct operation and longevity of your product.
This product is precision-engineered. Any work on it should be performed in a clean environment. The manufacturer is not responsible for damage caused by improper adjustment or disassembly.
2. Safety Information
General Warnings
- WARNING: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
- Always ensure all screws are tightened properly before starting the engine.
- Keep away from open flames to avoid unwanted fire.
- If any information in this manual remains unclear, seek professional advice.
3. Package Contents
Upon opening your package, please verify that all the following items are included:
- 1 x Throttle Grips Assembly
- Necessary mounting hardware (screws)
- Throttle Cable (if included with specific model)
Note: The exact contents may vary slightly based on the specific product variant purchased.
Figure 3.1: Complete accessories included for easy installation.
4. Specifications
| Feature | Description |
|---|---|
| Brand Name | NIBBI |
| Motobike Make | Universal |
| Origin | Mainland China |
| Material | Aluminum Alloy / Plastic |
| Surface Color | Black |
| Total Length | 155mm |
| Inner Diameter | 22mm (7/8") |
| Outside Diameter | 26mm |
| Throttle Sensitivity | 1.9° throttle rotation moves cable 1mm |
| Total Throttle Travel | 50mm (achieved with 95° rotation) |
| Fitment | Most motorcycles, Dirt Bikes with 7/8" (22mm) handlebars |
Figure 4.1: Key dimensions of the NIBBI throttle grip.
Figure 4.2: High Sensitivity feature of the throttle grip.
Figure 4.3: Ergonomic design for easy operation.
5. Installation
The NIBBI throttle grips are designed for easy installation. Follow these steps carefully:
- Disassembly: Carefully remove the existing throttle grip and housing from your handlebar. Loosen any screws holding the housing together.
- Cable Removal: Disconnect the throttle cable from the old throttle tube. Note how the cable is routed and connected to the throttle tube and carburetor.
- New Cable Installation (if applicable): If replacing the cable, route the new cable through the housing.
- Throttle Tube & Cable Connection: Insert the throttle cable end into the new NIBBI throttle tube. Ensure the cable is properly seated in the groove of the throttle tube.
- Housing Assembly: Place the throttle tube with the cable into the NIBBI throttle housing. Align the two halves of the housing and secure them with the provided screws.
- Handlebar Mounting: Slide the assembled throttle grip onto the handlebar. Position it correctly and tighten the screws to secure it firmly, but allow for smooth rotation.
- Cable Adjustment: Connect the other end of the throttle cable to the carburetor. Adjust the cable tension to ensure proper throttle response without binding. There should be a small amount of free play before the throttle engages.
- Test: Before riding, thoroughly test the throttle for smooth operation, full range of motion, and proper return to idle.
For a visual guide, please refer to the installation video below:
Video 5.1: Step-by-step installation of the NIBBI throttle grip and cable.
6. Operation and Carburetor Tuning
The NIBBI throttle grips provide precise control, which can be optimized by proper carburetor tuning. The carburetor's function is affected by factors such as air pressure, temperature, humidity, and altitude. This section provides basic tuning principles.
Basic Tuning Common Sense
- Air Screw: Clockwise rotation of the air mix screw makes the mixture leaner. Anti-clockwise rotation makes the mixture richer.
- Main Jet: A bigger main jet results in a richer fuel mixture.
- Pilot Jet: A bigger slow jet results in a richer fuel mixture.
- Jet Needle: There are five options per needle; a higher number generally indicates a richer mixture. The throttle valve is inversely proportional to fuel concentration. If the throttle valve angle is small, the fuel is rich; otherwise, it is lean.
Tuning for Throttle Opening
- Closed to One Quarter Throttle Opening: Adjust the mixture by changing the slow jet according to the air input. Set the air adjustment screw to adjust the mixture for low-speed running.
- One Quarter to Three Quarter Throttle Opening: Adjust the mixture by changing the jet needle position according to the air input.
- Three Quarter to Full Throttle Opening: Adjust the mixture by changing the main jet according to the air input. For high-speed running, change the power jet to adjust the mixture.
- Half Throttle to Full Throttle (High Air Speed): Adjust mixture by changing the main jet, jet needle, or jet needle setting. Always check the spark plug to confirm correct settings.
Important Note: Running your engine too rich will reduce performance, while running it too lean can cause severe damage to engine components (piston, cylinder, head). Always start on the rich side and gradually lean out the mixture for optimal performance. Change only one factor at a time and assess the changes.
For detailed carburetor instructions, you can refer to the official NIBBI Carburetor Instruction PDF: NIBBI Carburetor Instruction Manual (PDF)
7. Maintenance
To ensure the longevity and optimal performance of your NIBBI throttle grips and associated carburetor, regular maintenance is recommended:
- Cleaning: Periodically clean the throttle housing and grip area to prevent dirt and debris from interfering with smooth operation. Use a mild cleaner and avoid harsh chemicals.
- Lubrication: Apply a suitable lubricant to the throttle cable and internal moving parts of the throttle housing to ensure smooth action and prevent wear.
- Inspection: Regularly inspect the throttle cable for fraying, kinks, or damage. Check the throttle housing for cracks or loose components. Ensure all screws are securely fastened.
- Carburetor Maintenance: If you are also maintaining the carburetor, ensure jets are clean and free from blockages. Check the air filter regularly and clean or replace as needed.
8. Troubleshooting
This section provides common issues and their potential solutions related to throttle and carburetor performance.
| Problem | Symptoms / States of Mixture | Setting / Solution | Notes |
|---|---|---|---|
| Between closed throttle and one-quarter throttle opening | Rich: Acceleration is hesitant or irregular. | Change the needle jet to a smaller one to make the mixture leaner. | Check basic knowledge & adjustment. |
| Lean: Engine brakes. | Change the needle jet to a bigger one to make the mixture richer. | Check basic knowledge & adjustment. | |
| Throttle between one-quarter and half open | Rich: Engine bogs. | Change main jet to a smaller one. | A piston ring could be worn, or too much advance. |
| Lean: Engine pings, detonation. | Change main jet to a larger one. | Check spark plug color. May also be an air leak in the inlet tract. | |
| Throttle is fully open | Rich: Engine speed rises erratically, engine feels flat. | Adjust mixture by using a smaller main jet. | Air filter could be blocked. Check choke is not stuck. |
| Lean: Spark plug is dry and white. | Adjust mixture by using a larger main jet. | Spark plug should be brown. | |
| When idling | Lean: Engine runs erratic, RPM is not stable. | Turn air screw in clockwise to make mixture richer. Change to a bigger slow jet. | Possible broken reed petal or air leak in inlet tract. |
| Rich: Engine is stalled, exhaust fumes are black. | Change to a smaller slow jet. Turn air screw out to make mixture leaner. | Check all parts involved. | |
| When riding away | Lean: Poor acceleration. | Change to a bigger main jet. | |
| Rich: Engine runs erratic. | Change to a smaller main jet. | ||
| Between closed throttle and one-quarter throttle opening | Lean: Engine stalls. | Go for a thinner needle to make the mixture richer. Turn the air screw in clockwise to make the mixture richer. | |
| Rapid throttle opening | Lean/Rich: Check spark plug. | Adjust mixture. |
9. User Tips
- Quicker Response: The NIBBI throttle grip features a well-made roller bearing and a significantly shorter stroke compared to many factory grips, resulting in a quicker and more responsive throttle.
- Universal Fit: This product is designed for universal fitment on most motorcycles, pit bikes, bicycles, and ATVs with 7/8" (22mm) handlebars.
- Quality Construction: Users have noted the well-made construction of the throttle grips, indicating durability and reliability.
10. Frequently Asked Questions (FAQ)
- Q: What types of vehicles is this item compatible with?
- A: This product is designed for universal use with Bicycles, Bikes, ATVs, Pit Bikes, and Motorcycles, specifically those with 7/8" (22mm) handlebars.
- Q: Does this throttle provide a '1/4 turn' acceleration?
- A: The NIBBI throttle grip features high sensitivity, with a 1.9° throttle rotation moving the cable 1mm. This provides a very quick and responsive acceleration, often perceived as a 'quick turn' throttle.
11. Warranty & Support
For any issues or questions regarding your NIBBI Universal Handlebars and Throttle Grips, please contact the seller or NIBBI customer support. Ensure you retain your proof of purchase for warranty claims.
For additional documentation, including a detailed carburetor instruction manual, please refer to the PDF available at: NIBBI Carburetor Instruction Manual (PDF)