Razor MX400 Review – Dirt Rocket with lighted valve stem Review

Razor MX400 Review – Dirt Rocket with lighted valve stem
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Our Rating: 7.4
48 reviews

Last updated October, 2019

The Mx400 electric motorcycle is a step up from the entry level dirt bikes, and is for slightly older (and/or heavier) kids.

Designed for children ages 13 and older, this bike goes a little bit faster and is a little bit larger.

It comes with 12″ pnuematic tires to help ride over rough terrain, and has a maximum weight capacity of 140 pounds.

For some reason, most reviews of the MX400 compare it to the MX350, and actually recommend people steer clear of this one and get the older MX350. Some of the complaints are the lack of suspension, and a jerky throttle rather than a variable speed like the older MX350 had. However, according to the Razor USA website, the MX350 and MX400 are the same motorcycle, they are just different colors. Perhaps the reviews are comparing an older MX350 with a newer MX400 model which leads to the confusion.

Riding Time30-40 minutes
SuspensionAir filled tires
Motor Power350 watt
Top Speed14mph
Weight capacity140 pounds
Weight62 pounds

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Guide to Buying an Electric Dirt Bike

Thinking of buying the Razor MX400 dirt rocket electric motocross bike? When you’re looking for an electric motorcycle, there’s some things to consider:

  1. What is your budget? It’s easy to get into the habit of thinking “For just $X more, I can get Y feature”. But pretty soon, you’re looking at an EV dirt rocket that is twice as expensive as what you wanted to spend. Picking a budget and sticking to it will keep price creep from happening.
  2. What type of riding are you hoping to do? If you’re staying in a cul-de-sac, or a grassy backyard in New Hampshire, your needs are different than someone who wants a little bike to check miles of fence line in the rugged terrain of central Nevada.
  3. How skilled, confident, and how strong is your child? Most electric motorcycles are recommended for older children. For example, the MX400 is recommended for children 13 years old and older. If your child is younger than the recommended age, take a look at the electric dirt bikes that have a parent-selectable top speed to enable your child to grow into the motorcycle.
  4. What sort of features are you looking for? Most of the electric dirt bikes reviewed have twist throttles, and some of the best dirt bikes for kids come with kickstands. It’s helpful to determine a list of features before you go shopping.

What is the difference between the MX350 and MX400? We were even confused about this at first, but according to Razor USA’s official website, the difference is simply in the color. Both are scaled down dirt bikes aimed for young riders to live off-road at speeds up to 14 mph. They’re completely the same, with large knobby pneumatic tires and fully rechargeable battery packs.

Often, the MX350 is cheaper because it’s common to think the MX400 has better / improved features.

Different Types of Dirt Bikes

Most obviously, there are gasoline powered and there are electric dirt bikes. Razor USA deals specifically with electric motorcycles for kids, and is the leader in the market for North America.

There is also sidewalk/city use style motorcycles for kids to learn on, and serious offroad motorcycles for little tykes to follow their parents out in the wilderness. Razor’s Dirt Rockets are somewhere inbetween. They can handle mild offroad use, such as a gravel road or a grassy field, but they wouldn’t handle deep puddles, steep loose dirt paths, or long mountain trails with roots and rocks.

What People Are Saying

Battery Life: Some buyers have complained about the battery life, but for buyers who actually had a defective battery pack, Razor was quick to resolve the issue. The other group of buyers seem to be heavier riders who cause the battery to die faster. This leads to the question of what weight the ’30-40 minute’ ride time is tested with?
One owner of multiple Razor electric motorcycles said that his 6 year old gets several more minutes ride time than his larger, heavier 8 year old.

Battery Range: Similar to battery life, this is largely affected by terrain, rider weight and riding style. Razor Company says the dirt rocket MX400 it can travel up to 10 miles on a single charge.

Charge Time: Based on owner’s comments, the battery pack takes about 5 hours to charge from nearly dead. Another owner lamented that charging took 11 hours, but they didn’t indicate if this was the initial charge time from completely dead or if this is the recurring charge time.

Top Speed: The Razor MX400 top speed is listed as 14 miles per hour on the Razor USA website. On some other retailer sites the speed is listed as 12 mph or 13 mph. Top speed can vary depending on the terrain being ridden on, and of course, the weight of the rider. There are no details as to what weight of rider the top speed is tested with, so that could be why there is some variance in the ratings.

Child Size and Recommended Age: Many Razor dirt bike reviews state how much they love the Razor, but don’t think the age recommendation is correct. One review states that they have a 10 year old child that is just over 5 feet tall and 100 lbs and says they are already too large to operate the bike safely. Another buyer says that his 95 lb 11 year old causes the bike to struggle going up a ridge their house is on, while the dirt bike handles the 45 pound 6 year old just about perfect.

Useful Tips for Buyers

Some minor assembly is required for the MX400 dirt rocket.

MX400 Dirt Rocket Resources

Pre-Ride Checklist Before each ride, to ensure safety, you should:

  • Make sure there are no loose parts or broken components
  • Ensure the tires have a good amount of air pressure, and that they aren’t warn and still have tread
  • Make sure the brake is operating properly
  • Check the frame, front fork, and handlebars for cracks or broken connections. It is possible, especially for an aggressive driver or after a crash, for a crack to develop. Check regularly to ensure a safe and enjoyable ride.
  • Always wear safety gear, including a safety approved helmet, and perhaps elbow and kneepads. Always wear closed toed shoes – never ride with sandals or bare feet. Make sure your shoelaces are tied and stay out of the way of the wheels, motor, and drive systems.

Troubleshooting Guide

Sometimes it works, other times it doesn’t: Check for loose wires and connections, and if all of them seem tight, contact a Razor dealer. There could be an issue with your motor or electrical switch.

During charging, the charger gets warm: This is normal. If the charger doesn’t get warm, that means it is not functioning properly and your dirt bike isn’t getting charged.

When applying brakes, the motorbike doesn’t stop: Make sure the brakes are adjusted properly. Refer to the user manual for instructions on how to do this.

Motor makes grinding or other loud noises: Apply lubricant to the drive chain.

Motorbike is sluggish or slow: This could be because the rider weight is too much for the bike, or because the terrain is too stressful. Use on solid, flat, clean surfaces. Also, ensure tire pressure is correct. Under inflated tires can create extra work for the electric motor.

Short Run Time of less than 15 minutes per charge: Charge the battery for at least 18 hours (for a new motor bike) and at least 12 hours each time afterwards. If there is still no change, check for correct tire pressure and make sure the brake isn’t dragging during normal driving. It is possible that the battery could need replacing. Average battery life is 1 to 2 years depending on product use and conditions.

I was driving my electric dirt bike and it suddenly stopped: Check to make sure the fuse isn’t burned out. If it is, replace with a new one of the correct/equal amperage rating. If the fuse isn’t burned out, check to see if a wire connection pulled apart. Then contact your Razor authorized service center.

Parts If you ride your Dirt Rocket the way it was meant to, hard and often, then chances are you’ll eventually need to buy some parts. The best place to get them is straight from the manufacturer. Check out the Razor USA site for MX400 Parts It’s the best place to get genuine replacement parts like Razor batteries, brakes, twist grip throttles, e-kits, etc.

User Manual MX350, MX400 User Manual PDF is available for free download from here

Limited Warranty All of Razor’s Dirt Rocket electric motorcycles come with a 90 day limited warranty. It does not cover wear and tear, tires, tubes, cables, or damage caused by a crash. The warranty is also void is the dirtbike is used for anythign other than recreation, including renting it out, or attempting to tow or exceed weight limits.

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