Motivation and Research

Background
I have spent much of time and energy researching and implementing an electric go kart for my son's 8th birthday. I have to thank the Internet community for all of the information I needed to do the job. I thought I would repay the debt by providing pictures, videos, and descriptions of what I have learned.

I started by doing a search online of electric go karts that I could buy. You may ask, why not just go with a gas go kart? The fact is that gas go karts are fun, I had one as a child. Along with the fun, there are many potential issues. First (per my wife) is the smell of gasoline in the garage. Other issues are the difficulty in starting especially for a small child. There are maintenance issues as well. For many reasons, I decided to go for an electric option.

Available (New) Electric Go Karts
So there are 2 ready made designs that I considered:

Doesn't get great reviews but not a bad option. here are the specs:

Product Description

The MotoTec Solar Electric Go Kart provides up to a 2 hour ride time with its integrated 4watt monocrystalline silicon solar panel on the rear wing that continuously recharges the go kart while in use. It's powered by a 16Ah 24v battery pack and 350 Watt DC motor that can reach speeds of 15mph. The solar panel can also charge the go kart while not in use or with the battery charger in 4-6 hours. This go kart comes standard with 9 inch pneumatic tires for a variety of terrain and easy to use disc brakes.

Motor: 350 Watt DC Electric Motor
Top Speed: 15 MPH
Battery: Two 12v 16AH Lead Acid (24V total)
Solar Panel: Integrated 4W Monocrystal Silicon (13x9 inch panel)
Battery Charger: Included
Ride Time: 2 Hours (compared to 45min)
Frame: Steel
Rims: Aluminum 2 piece
Tires: 9 inch Pneumatic (9x3.5-4)
Brakes: Rear disc with hand lever
Green: Zero Emissions
Recommended Age: 12+
Max Rider Weight: 150 lbs
Product Dimensions: 48x33x21 inches
Product Weight: 80 lbs
Box Dimensions: 49x35x15
Box Weight: 103 lbs
Warranty: 30 days parts replacement

The next Item that I considered is the

The Razor gets 4 stars but it seems a little puny. Some of the reviews mentioned that the rear wheels could be damaged by hard turning and seem to wear out easily. On the plus side it is inexpensive.

Here is the product description from Amazon:

Amazon.com Product Description

Want to give your child a little off-road entertainment? Turn to the Razor dune buggy, the ultimate in electric-powered backcountry cruising. Outfitted with a powerful 350-watt motor designed to reach speeds of up to 10 miles per hour, the buggy is fast enough for serious fun, but slow enough that it won't compromise your child's safety. Parents will also appreciate the side roll cage, which creates a barrier between the rider and the outside, and the padded bucket seat, which includes a seatbelt for added security. And thanks to the buggy's specially designed reduction drive, the vehicle is capable of both lower torque climbing and high torque gearing. Perhaps the coolest feature, however, is the fully electric design, which is not only easy to charge, but requires no fuel at all, runs quietly, and produces no emissions.Other details include eight-inch knobby pneumatic tires, an active rear suspension, a durable tubular steel frame with diamond-plate floorboards, hand throttle and brake controls, a rear disc brake, and a safety flag. Ideal for difficult tracks and terrain, the buggy supports up to 120 pounds of weight and is suitable for ages 8 and older.

Key Features:
For ages 8+
220-pound weight limit
Can reach speeds of up to 10 miles per hour
350 watt motor
8 knobby pneumatic tires
Bucket seats with seatbelt
Powder coated finish on tubular steel frame
Protective padding
Diamond plate floorboards
Hand throttle and brake controls
Rear disc brake
Safety flag
Vertical storage

Product Description
The Razor Dune Buggy provides the ultimate in electric powered off-road capabilities. Powerful speeds up to 9mph and can carry up to 120lbs ! The Dune Buggy's specially designed reduction drive is perfect for lower torque climbing and off-roading. 8" knobby tires and big bucket seat allow for a smooth comfortable ride. Ages 8+

Comparison
So to compare the two options, Both have 350 watt motors and 24 volt systems. The razor has only 7ah batteries vs 16ah for the Mototec. The Mototec is more expensive and bigger, but with worse reviews and manufactured by a brand that I do not recognize and is not sold in stores. The other is smaller but probably more reliable overall and I could buy it from ToysRus if I choose so that I could easily return it. The Mototec does have a solar panel but I think that has limited usefulness.

Research:
Neither options perfectly fit my needs so I decided to research how to build my own electric go kart. Some of the sites that I visited are:


http://www.instructables.com/id/How-to-Build-a-Custom-Electric-Go-Kart-and-Brushle/

This one is about the Eli-kart. It is by an engineer with vast resources which I do not have. Good info and ideas but hard for me to implement.


http://www.evalbum.com/2708

This one is about the HDT Kart. It is a kettler kettcar converted into an electric go kart. It seems like a death trap. I think the ideas are very good but the frame is to puny for the power. Also, they used a Ramsey winch motor. This is not a good idea since those motors are not meant to be used continuously, they will overheat and die. Same goes for starter motors which many hobbyists are using.


Youtube has tons of videos showing electric go karts. Many are using golf kart motors, high amperage controllers (400A), and tons of batteries. They do some amazing burnouts and stuff.


One example is the Neurotikart II:

Be sure to read the comments, the author explains what parts he uses.

This next one shows a 70,000 watt motor from an electric fork-lift. It has a 1000A controller and goes about 100MPH.

The best single reference for building electric go karts is definitely the DIY Go Karts forum:
http://www.diygokarts.com/vb/showthread.php?t=14794
They go into details as to what batteries to use, what motors work, how to figure out gearing, controllers, etc. You can learn all you need to know there.

Honda MiniMoto

Honda MiniMoto Go Kart, image from Amazon, no longer available

The other option I considered was buying a used Honda MiniMoto Go Kart (picture above). These are really cool vintage go karts. Here is a link to the discontinued Amazon listing: http://www.amazon.com/Minimoto-23291-Go-Kart/dp/B0001NE7DC/ref=cm_rdp_product . You can read the reviews and the specs. It has a 500 watt motor with a 36 volt system. It goes 18mph and can support an adult. It is a shame that they do not make anything like that anymore. The current commercial offerings pale in comparison.

I searched for a while on Ebay and Craigslist for a MiniMoto in decent condition. They are very expensive and hard to find. I found one on Long Island (about 100 miles away) and was considering paying my brother to pick it up but I decided against it at the last minute. Too much distance, and what if the item does not match the description. I gave up on the go kart and was starting to consider the Honda MiniMoto motorcycle:

They are much easier to find. I found a nice example only 45 minutes away for $300 on Craigslist. My wife convinced me out of it (not really but I didn't think it was worth the fight). She thinks that a mini motorcycle is like a gateway drug to a real motorcycle and she doesn't even want to imagine my son riding a motorcycle.

Next post I will go into my project.