Go Kart for Big Kids

I few years ago I bought a used Razor Ground Force Drifter go kart for the kids.  The didn’t ride it much and after less than a year it broke. Rather than just fix it, we decided to supercharge it.

Muwhahaha

 

Here’s what you’ll need.  

1. 1000w 48v motor
2. 1000w 48v motor controller
3. 2 more 12v/9ah batteries (4 total)
4. 48v charger

 

I bought a kit from ebay that included the motor/controller/charger, and a throttle and key switch for $175.  The batteries can be bought for $15-20 each. I don’t remember what I paid for the go kart, but I’ve seen some for sale for between $150-$200.

 

First step is to take it apart. Take out the batteries, motor, controller, and the seat. We’ll use the seat and batteries.

The motor I bought fit pretty well where the old motor had been. I did need to drill new holes, and eventually I had to raise the motor a little to get the chain to fit tight.

I wanted to put the batteries under the seat. So I used some 6” bolts to raise the seat about 4 ½”. I was worried about the lateral force on those screws so I added some metal strapping diagonally.

The motor controller fit in almost the same place as the old one. Having the motor and controller in those places, and the batteries under the seat, I could use the old motor cover to keep things hidden away. I had to cut some of the motor cover to make room for the strapping, and I raised it up a little to give more clearance since I had also raised the motor.

The charging connector fit in the same place. And I mounted the key switch here.

The labels that came on the new motor controller weren’t super clear, but with a little experimenting I figured out which wires to connect to the brake and the throttle.

The blue and yellow wires from the controller go to the motor. And the Red and black go to the batteries.

The whole project only took about 8hrs, and a lot of that was figuring out how to raise the seat and firing out the wiring.  If I do another one, it would only take a couple hours.

After the first test drive I decided to tighten the brakes.

I had to hot glue the battery connectors too.  I think the seat was knocking them off during some of my 4g turns.

 

Performance:

Top Speed 19-20mph

Battery duration 37min

 

That’s about it.  Super fun and really easy.

 

Description:

Razor made these Ground Force go-karts a little too weak.  Here’s how I modified ours to make strong enough for an adult to ride and enjoy.

 

Parts:

1. Razor Ground Force go-kart
2. 48v 1000w motor
3. 48v 1000w motor controller
4. (4) 12v 9ah batteries [it comes with 2 so you’ll need 2 more]
5. 48v battery charger
6. (6) ⅜” x 6” bolts w/ 3 nuts, 3 washers and 3 lock washers per bolt (18 total of each)
7. (2) 1’ lengths of ½” conduit to make the seat support bars
8. 16g metal strapping for crossing supports (about 4’ total)
9. #25 roller chain connector link (Chain break tool, if you don’t already have one)

 

Steps:

1. Remove the seat, motor cover, motor controller, and motor.  Keep the motor controller, you’ll use some of the connectors.
2. Place the new motor on the old motor mounting plate and mark locations for new holes.
3. Fit the chain on the motor and drive gear.  If it doesn’t fit well, adjust it by lengthening the chain and/or raising the motor using chain connector links and washers.
4. Lift the seat using the 6” bolts. Drill holes for new farther-back bolt. Adjust nuts so the seat is at least 4 ½” above the base of the go kart frame.
5. Place cross supports. I used 16g metal strapping, you could use ½” conduit or something else you have handy.
6. Place 4 batteries between the crossing supports. Wire in series (+ to -)
7. Secure Motor controller
8. Make electrical connections (use motor controller wiring diagram or labeled connectors):
   1. Charger
   2. Brake
   3. Throttle – Should be red/green/black wires
   4. Power switch
   5. Batteries – Large red and black wires; Solder and Hot Glue connections
   6. Motor – Blue (controller) to Red (motor) and Yellow (controller) to Black (motor)
9. Test power switch, throttle, and direction of wheels.
10. Secure all wires, replace motor cover, raise motor cover if sprocket and chain are rubbing.
11. Replace seat and seat belt.
12. That’s it!  Go have some fun!