Nothing ruins a leisurely ride on your motorized bike like excess engine vibration. Not only is it annoying when your motorized engine vibrates at an unreasonable level, but it can also cause riders pain and potential damage to the bike itself.
Many 2-stroke and 4-stroke motorized bikes have a built-in counterbalanced engine designed to minimize vibration. Unfortunately, this solution often leaves a lot to be desired, and many riders still experience significant levels of vibration while riding.
If you want to make the most of your motorized bike riding and avoid potential issues, you’ll need to decrease your engine’s vibration. In this article, we’ll explain the problems your motorized bike can experience as a result of too much vibration, as well as tips for reducing your motorized bike engine’s vibration.
Photo: BikeBerry (Facebook)
Why You Should Reduce Your Engine Vibration
Whether you have a 2-stroke engine or a 4-stroke engine, vibration is hard on several key components of your bike, engine, and studs. Over time, vibration will wear down on these parts, which means you’ll need to get them replaced more frequently. Moreover, vibration can also decrease your bike’s performance, leading to a lower-quality ride.
In addition to decreasing the longevity and durability of your motorized bike and its engine, excessive vibration can also lead to hand pain and fatigue. This is especially true when riders go on longer rides or reach high speeds on their motorized bikes.
While engine vibration is natural and will never be completely eliminated, high levels of vibration can result in any of the following issues:
Excess motorized bike engine vibration can cause screws and bolts to loosen.
Strong vibrations can cause motorized bikes to become cracked or chipped over time.
If you want to make the most of your motorized bike, extend the longevity of your bike’s parts, and have a quality ride, you will want to address any unnecessary engine vibration immediately.
- Frame and motor damage. As a 2-stroke or 4-stroke engine vibrates against the mount and bicycle frame, it will cause damage including scrapes and even cracks over time.
Frequent replacements. Excessive vibration also weakens the motor itself, which decreases its longevity. This means you will have to replace your motor — as well as parts like your motor mount and mount studs — far more frequently than you would if you simply reduced unnecessary vibration.
Major engine issues. While strong vibration can lead to problems, in some cases engine vibration is an indicator of existing issues. By ignoring this vibration, you will not be able to address and resolve these engine problems before they escalate into a major problem that will possibly require a costly fix.
Ways to Reduce Engine Vibration
If your engine’s vibration is causing you frustration and taking the fun out of your motorized bike riding, you’re not out of luck. There are a few rather simple adjustments you can make and add-ons you can install that will make a huge difference when it comes to minimizing your engine’s vibration. Below we’ve outlined a few steps you can take that will help you reduce your motorized bike engine’s vibration and increase the overall quality of your ride.
1. Install Rubber Vibration Motor Mounts
One of the best and simplest ways to immediately resolve your 2-stroke engine’s vibration issues is to install a vibration motor mount. These tools provide extra support for the bike’s frame, which in turn reduces vibration and protects the bike’s engine.
Your motor mount is what supports the engine on a motorized bike frame. If you have a metal mount, the rattling of that mount against the bike frame will cause significant vibration and increase the likelihood that your mount and mount studs will be cracked and ruined over time.
Alternatively, you can place a thin lead sheet between your mounting hardware and your bike’s frame to reduce this rattling, and this works moderately well. That said, using a rubber motor mount is much more beneficial as it will significantly decrease the amount of vibration you experience while also improving the longevity of your bike’s engine, frame, and the mount itself.
Installing a rubber motor mount is a simple solution, and it doesn’t require you to make any alterations to your motorized bike. Once installed, you’ll notice a difference right away.
Some rubber mounts, such as the BBR Tuning Vibration Motor Mounts, offer both front and back support. By utilizing two rubber pieces versus just one, these vibration motor mounts help reduce engine vibration by as much as 75 to 85 percent.
Typically, BBR Tuning Vibration Motor Mounts include the rubber mounts themselves, lock nuts, washers, and lock washers. Installation is straightforward, too — all you’ll need is a Phillips screwdriver and an Allen wrench. Simply use these tools to remove your metal motor mount and replace it with the new rubber vibration mount.
If you’re looking for a cost-effective solution to your engine’s vibration problem, you should consider buying rubber vibration motor mounts for your motorized bike.
2. Port and Polish Your Cylinder
One of the most effective ways to reduce your motorized bike’s vibration is to port and polish your engine's cylinder. This can help you improve your motorized bike’s performance and eliminate excess vibration without installing any upgrades.
When you port and polish your 2-stroke cylinder, you’re simply enlarging and smoothing out your bike engine's intake, exhaust, and transfer ports, allowing them to take in and expel air more efficiently. This means your engine will not have to work as hard as it normally would to take in air and eliminate exhaust gases and fumes. As such, it will operate much more smoothly, causing it to vibrate less.
Check out our step-by-step guide on how to port and polish your 2-stroke engine here.
3. Balance Your Engine’s Crank
Another way to decrease vibration and protect your motor without having to purchase and install new parts is by balancing your bike engine's crank.
When your engine’s crank is balanced, it simply means there is enough counterweight to offset the weight of the moving parts in your engine. With a properly balanced crank, the inertia between the reciprocating and rotating parts in the engine will be balanced, as well, which will reduce the engine’s vibration and help your motor operate properly.
When your engine’s crankshaft is unbalanced, it will cause significant engine vibration. So if you are experiencing higher levels of vibration than normal, you should check your engine’s crank.
4. Install a Boost Bottle
If you have a 2-stroke motorized bicycle engine, you can use a boost bottle — like the BBR Tuning Single Boost Bottle Induction Kit — to help reduce engine vibration. Boost bottles prevent any leftover air-and-fuel mixture from reentering the intake cycle when your engine draws fuel by containing this mixture and then using it to provide a “boost” of atomized fuel to the bike’s engine.
This process helps reduce vibration by expanding your motorized bike’s intake area and allowing the intake cycle to run on fresh air instead of a previously burnt air-and-fuel mixture. This allows the engine to run smoothly, decreasing the vibration on both your motorized bike engine and handlebars.
5. Performance Parts and Tuning Your Engine
In addition to porting your engine in order to increase airflow, tuning your engine will help you better control the airflow entering your engine, which will help address vibration issues.
An exhaust muffler with a tuned expansion chamber, performance carburetors, or exhaust parts with a baffle-less design will help your engine expel exhaust and fumes more efficiently, as well as decrease unwanted vibration. However, if you don't know how to pair performance parts and tune them, you're going to cause more vibration then ever before.
There are two methods of engine tuning that you should consider in order to reduce vibration:
Photo: BikeBerry (Facebook)
Carburetor tuning. If your carburetor is not tuned, it can actually restrict airflow. The first thing you'll want to do if you're not getting enough air (and subsequently, fuel) is to tune your carburetor. That involves adjusting the c-clip on your jet needle, adjusting your idle via the idle screw, and making sure your float kit is level. Don't worry, we have a video guide on how to tune your carburetor.
- In addition to simple tuning, you may also need to adjust the fuel jets in the carburetor. If you have high performance parts, new jetting will be especially necessary, as jets allow you to control the amount of air/fuel entering your engine for proper running.
.61mm .62mm .63mm .64mm .65mm jets are small and restrict a good amount of air and fuel. These are good for bikes that need a minimum amount of air and fuel going into their motor.
.66mm .67mm .68mm .69mm .70mm jets are larger and restrict less air and fuel. If you're on a high performance bike that takes in large amounts of air and fuel, these are the jets you'll want to work with.
.71mm .72mm .73mm .74mm .75mm jets are pretty big and let in a good amount of air and fuel. These are for upgraded engines that take in vast levels of air and fuel when riding.
Balancing intake and exhaust. This will ensure all of your engine’s parts are working together as effectively as possible, which will help get rid of unwanted engine vibration. That means making sure that your carburetor is taking in lots of air, your cylinder is ported, and your exhaust is wide enough to let out a lot of exhaust.
It might seem beneficial to get a high-performance carburetor with large jets and an idle screw, but if you don't couple it with a high-performance muffler capable of expelling large quantities of exhaust and fumes, then you’ll actually make your vibration problems worse by creating a bottleneck of air that’s trying to escape your engine.
Reduce Your Motorized Bike Engine’s Vibration for a Better Ride
With the modifications and add-ons listed here, you’ll quickly notice an improvement when it comes to your motorized bike’s engine vibration. Remember, even though most of these alterations are simple, they can cause damage to your motorized bicycle and your engine if not done properly.
Whether you follow one or all of these guidelines, you’ll experience a better, smoother ride. Step up your motorized bike by implementing one or more of these vibration reduction tips today.
Photo: BikeBerry (Facebook)
“Most of these tips seem to revolve around 2 stroke engines. Can you post more tips for the 4 stroke engines?
Balance the crank, and- run the proper ignition advance. rubber mounting ‘band aids’ don’t really cut it. Mine runs to 7800 rpm- and smooth. Oh, and don’t use crap gas. Two stroke oil drops octane in the fuel. At 1oo mpg+ anyone can afford premium grade fuel
I learned some very good tips to help my bikes run their best.
Take a black solid rubber Bungee cord and cur the 3/16" rubber and place it as a motor mount in the 4 stroke engine not 2 stroke, works great!