Coleman Mini Bike Torque Converter Guide: Improving Acceleration and Top Speed

A torque converter is one of the most popular and effective performance upgrades for a Coleman mini bike. Installing a torque converter smooths power delivery and helps maximize acceleration from a standstill. Experienced mini bike enthusiasts know that the right torque converter can transform a slow, clunky ride into a thrilling high performance machine.

In this article, we’ll explain what a torque converter is, how it works, and the benefits it provides on a modified Coleman mini bike. We’ll cover how to select the right torque converter kit and walk through the installation steps. We’ll also discuss tuning and maintenance to keep your converter operating at peak efficiency. Let’s get into the torque!

What is a Torque Converter?

A torque converter is essentially a variable transmission that sits between the engine and clutch on vehicles like mini bikes and go karts. Inside a sealed housing, a torque converter contains:

• An impeller connected to the engine’s crankshaft
• A turbine coupled to the output shaft leading to the clutch and transmission
• Stator blades between the impeller and turbine

The interaction between these components transfers rotational force from the engine to the output shaft. But unlike a mechanical clutch, the torque converter does this fluidly via transmission fluid without a fixed connection.

This gives two key benefits:

1. Allows the engine to reach higher rpm before engaging the drivetrain. This improves acceleration.
2. Multiplies torque, allowing smaller engines to drive larger tires/gearing combinations for higher speed.

In short, bolting a torque converter onto your Coleman mini bike before the clutch gives a significant performance boost. The converter broadens the engine’s powerband.

How Torque Converters Work

The genius of a torque converter lies in the stator. This acts as a variable link between the input side impeller and output side turbine:

From 0 rpm – At low speeds, the stator blades don’t allow transfer of much motion from impeller to turbine, so the engine can rev freely.

As rpm increases – The stator blades progressively lock up, transferring more force to spin the turbine faster. This boosts acceleration.

At high rpm – The stator locks fully, creating a near 1:1 drive between impeller and turbine. This multiple torque effect allows climbing to higher road speeds.

When slowing – The stator unlocks, again allowing the engine to rev without loading down the drivetrain.

This variable coupling effect broadens the engine’s usable rpm range and powerband. The result is much crisper throttle response and acceleration. Plus higher top speeds with the same engine.

Benefits of Adding a Torque Converter

Here are the key benefits of installing a torque converter on a Coleman mini bike:

• Faster Acceleration – Allows the engine to rev up before engaging the wheels. This minimizes lag time and reduces clutch slipping.
• Increased Top Speed – Takes advantage of the torque multiplying effect to reach higher road speeds using same engine rpm.
• ** Smoother Operation** – The fluid coupling softens clutch engagement improving smoothness and reducing stall risk.
• Better Drivability – Keeps the engine torque in its sweet spot improving throttle control and drivability.
• Traction Gains – The controlled engagement helps limit wheel slipping and improves traction.
• Engine Protection – Reduces stressed placed on the engine by preventing lugging at low rpm under load.

For both stock and modified engines, adding a torque converter accentuates the engine’s strongest performance range. The bike becomes more fun to ride and rewarding to control.

Selecting a Torque Converter for Your Coleman Mini Bike

The key to achieving those benefits is choosing the optimal torque converter to match your Coleman’s engine and intended usage:

• Engine Displacement – Size the torque converter capacity based on engine cc’s. Shoot too small and it will overload. Too big hurts acceleration.
• Clutch Configuration – Common options are for a #30, #35, #40, or #41 style clutch. Measure bolt patterns to determine fitment.
• Riding Style – More aggressive riding demands higher stall rpm models to keep the engine revving in its powerband.
• Tire Size – Bigger diameter tires require more torque capacity. Factor in any wheel and tire upgrades planned.
• Transmission Type – Consider gearing and whether the transmission is automatic or manual shift.
• Build Stage – Account for any engine modifications like big bore kits that increase displacement and power.

The manufacturer recommendations are a good starting point. Fine tune your choice based on your Coleman’s particulars.

How to Install a Torque Converter

Here is an overview of the key steps to install a torque converter on your Coleman mini bike:

1. Determine the optimal mounting location on the engine or jackshaft. This varies by model. Measure carefully.
2. Remove the clutch and thoroughly clean the mounting surface of old gasket material.
3. Bolt the converter onto the mounting plate loosely using the provided hardware kit. Use threadlocker on the bolts.
4. Check that the converter rotor spins freely by hand pre-assembly. This verifies proper fit.
5. Mate the converter rotor to the end of the engine crankshaft. Use the supplied spacer and shim washers to eliminate play.
6. Tighten all converter mounting bolts incrementally in a crisscross pattern to spec. Proper clamping is critical.
7. Bolt the clutch onto the converter using the existing clutch bolt holes and provided hardware. Shim as needed.
8. Refill the converter with manufacturer specified fluid to the full line.
9. Start bike and inspect for any leaks at mounting faces. Let run 5 minutes to circulate fluid and expel air bubbles.

Be sure to follow the included directions closely on your specific kit. Taking the time for careful assembly will be rewarded with dramatically improved acceleration and speed.

Tuning and Maintaining Your Coleman Mini Bike Torque Converter

Once installed, a few best practices will keep your torque converter performing optimally:

• Closely follow break-in instructions when new – don’t immediately hammer the throttle. Allow parts to wear in.
• Check fluid level regularly. Maintain at the full line specified by manufacturer. Change fluid every 150 riding hours or according to schedule.
• Listen for abnormal noise indicating loose fasteners, worn bearings, or other issues. Address promptly.
• Keep the exterior housing clean since it dissipates heat. Clean off accumulated dirt and mud which act as insulation.
• Check converter bolt torque and shim gaps periodically to prevent developing play from use.
• Use only manufacturer approved transmission fluids to avoid corrosion, viscosity breakdown, and leaks.
• Consider adding an engine temp gauge to monitor conditions that could prematurely break down fluid.
• Upgrade cooling if adding a torque converter to a higher output engine to handle the additional heat and work.

Proper tuning and meticulous maintenance will gain maximum transmission life even under aggressive riding. Think of the converter as an integral part of the engine system.

Troubleshooting Common Torque Converter Issues

If drivability problems arise, check these potential root causes:

• No or delayed engagement – Low fluid level, worn or stuck stator, engine underpowered for converter size.
• Rough engagement – Air trapped in converter, inadequate fluid viscosity, engine vibration transferred.
• Slipping after engagement – Worn or broken stator/turbine, low fluid level, insufficient shims/spacing.
• Overheating – Debris blocking cooling fan, inadequate fluid level/condition, undersized converter.
• Noise – Empty or insufficient fluid, loose mounting hardware, worn bearings/seals.
• Leaks – Damaged seals, cracked housing, loose hardware, gasket failure.

Carefully assess the specific symptom and potential causes before attempting repair. Improper torque converter service can do more harm than good. Seek professional assistance if needed.

Coleman Mini Bike Torque Converter Maintenance Tips

Here are quick tips for keeping your Coleman mini bike torque converter in top shape:

• Change fluid every 100-150 riding hours – more often in dusty or muddy conditions
• Choose a high quality automatic transmission fluid with proper viscosity
• Inspect for leaks each ride – address quickly to prevent bigger problems
• Check mounting hardware torque – vibration can loosen bolts over time
• Keep the external housing clean – buildup acts as insulation hurting cooling
• Consider adding a transmission oil temperature gauge for monitoring
• Allow proper warm up before hard acceleration – don’t hammer right after start up
• Listen for new noises indicating potential bearing wear or other developing issues

Staying diligent with proper maintenance ensures your torque converter delivers performance and durability to match the upgrade cost.

Coleman Mini Bike Torque Converter FAQs

Here are some common FAQs about torque converters for Coleman mini bikes:

What about gearing changes with a converter?

The torque multiplication effect allows using taller gearing than stock. Adjust to find the optimal ratio for acceleration versus top speed.

Can I add a torque converter to an engine without a clutch?

Yes, as long as there is a way to rigidly couple the converter. Some adapter plates may be required.

Do I need to upgrade engine cooling?

Adding a temperature gauge is recommended to monitor conditions. Improved airflow from a performance intake often resolves any cooling issues.

How much maintenance do torque converters require?

Change fluid every 100-150 riding hours. Check external cleanliness, fluid levels, and listen for noises regularly. Periodically inspect hardware.

What happens if I accidentally run it empty on fluid?

Running dry can quickly damage the bearings and other internal components. Top off the fluid immediately if low.

Can torque converter components be repaired or rebuilt?

Yes, in most cases individual components like bearings, seals, and clutch components can be replaced to restore a converter.

Wrapping Up Coleman Mini Bike Torque Converters

Adding a torque converter to your Coleman mini bike is one of the best bang-for-buck performance upgrades available. The variable transmission provides a smoother, more useable powerband that maximizes acceleration and speed. Just be sure to match your torque converter capacity to the engine output. Taking time for proper installation and ongoing maintenance will be rewarded with dramatically improved drivability. A quality torque converter kit tailored for a Coleman breathes new life into a stock bike or takes your modified machine to the next level. Feel that added snap each time you pin the throttle!