New Toy! Carter Trail Buster Go kart

At home in the barn

After coming back from a recent adventure I decided that my life needed a little more fun. A weekend in Atlanta and a visit to Andretti Karting led to gokarts. simple, easy to work on, and silly fun, I decided a gokart might just be what I needed. I started watching craigslist and ebay, eventually finding a decent looking off-road kart that was listed as ready to go. I called the owner and he gave me the details: 8 horsepower, new tubes in the tires, just had a tune-up. a 45 minute drive later I was climbing into the seat of something I barely fit in while the 8hp briggs chugged behind me. A short romp around his yard and I was grinning ear to ear.

Sold!



Cash changed hands and home it came, sliding perfectly into the back of my truck.

New toy rides home

Closer inspection revealed a few issues with my new toy: The charging system on the engine is disconnected. The headlight's wiring harness and switches are gone. The electric start system is disconnected. The engine's governor has been altered to remove the rev limiter.

 I started doing some research. First I found out the model number, 1728, then I found the owner's manual and parts breakdown from Carter Brothers Here

Next I used the numbers stamped into the engine to find it's manual courtesy of Briggs & Stratton Here

Finally I found the manual for the 40 series Comet torque converter Here

I did some quick rigging with 3/4 galvanized steel pipe to reroute the engine exhaust, then went for a test ride. First thing is this 8hp Briggs with its updraft carb is really cold blooded, gotta be good and warm before it will pull very hard. I discovered that on flat ground this thing is scary fast for a twitchy kart that's at least 15 years old. So fast it made my eyes water.

Next I pulled into a large grassy yard. Riding off-road proved to be disappointing. The torque converter slipped and the belt smoked, and the kart just wouldn't get-up-and-go. I brought it back to the barn and tore it apart.

Disassembly and checking of the drive system

Counting teeth on the final drive sprockets revealed the final ratio at 12/54 with #41 chain. The Comet torque converter kicks in at a 2.44:1 ratio then spins down to a 1:1 ratio as the kart speeds up. This combined with the 22" rear tires explains why the kart struggled to get started on terrain but went so fast during the road test. Some quick math revealed a top speed over 50mph with these ratios. Adding to all this I found the belt was too loose and had burned under load. Adjusting it now did no good, it looks like its toasted.

The shopping list looks like this:
60 tooth axle sprocket
10 tooth jackshaft sprocket
New #41 chain
New torque converter belt

More to come later!