Budgeting Help!!! (please)

[kaylsy]

Hello! I am building a go kart in school with four other people with a budget of only $400. We are STRESSING over this budget. Here is our list of itmes and estimated prices so far:
Engine - $209

• https://www.amazon.com/4-Stroke-Hor...lpcontext&ref_=fplfs&psc=1&smid=AOU382QYXD9FL

Steering wheel - makeable
Steel tubing - own
Transmission

• Centrifugal clutch $25-20
• 1” Bore and 10 teeth for #420 roller chain

Wheels - own
Axels - makeable!
Steering shaft - $50
Tie rods- $50/tie rod

• The side with the steering shaft should be 1 cm shorter than the other

Spindles - $30/spindle
Disc brakes or drum brakes - $90/brake
Seat - sourced
Gas tank - on engine
Throttle - $12
Brake cables - $8/cable
Pedals - makeable
Gearbox - $89.47

• https://www.ebay.com/itm/4049705955...yXNFKsv41Bt3WzZVxwfM9SuTGZHt2G4U66el-m3V4Bqw0

Are there better, cheaper alternatives to any of these? Do we really need four disc brakes? That is totally out of our budget. We don't expect this car to go very fast and it will be built from plywood. We already have wheels and we are keeping that engine. How many tie rods do we need? How do we know which ones to buy? What about the spindles? PLEASE HELPPP we have never done this before!!! Is there anything else we need that isn't listed here? We are complete amateurs so pleaseee help!!!

 

[BaconBitRacing]

Calm down. Number one: do not build out of plywood. It will break, and it is incredibly unsafe. Make your frame out of steel and weld it! Most go karts only have brakes on the rear axle. If you can return that engine you can buy a predator 212 from harbor freight that would more suit your project.

 

[Functional Artist]

For your first go kart/build
...you don't need a (~$200.00) 420 engine (a ~$125.00) HF 212 would do fine)
...or a (~$100.00) gearbox
&
Just those (2) adjustments would save ~1/2 of your budget

Look on BMI karts (or Go Power Sports) website & compare prices

For example, a set of spindles (~$40.00)
https://www.bmikarts.com/Complete-Spindle-Set--4-12-x-58-_p_1319.html
&/or
Tie rods are just lengths of 5/16" rod that have threads added to the ends
...tie rod ends (~6.00 ea.)
https://www.bmikarts.com/516-24-Female-Tie-Rod-End_p_1475.html

 

[bob58o]

since you are on a tight budget…

get rid of the gearbox. Gokarts are pushed when they need to go backwards. You don’t need neutral if you use a centrifugal clutch or torque converter / Continuously Variable Transmission. A gearbox just adds cost and complicates things in my opinion.

If you can return the engine for a cheaper and smaller engine. Stuff for 1” shaft 420cc engines is more expensive than stuff for 3/4” 160-212cc engines.

Id look for an engine off some piece of equipment… Stuff usually comes up for cheap on places like FB Marketplace.

Snowblowers if in an area that gets snow.
What else? Pressure washers, Log splitters, … ? Maybe pressure washers have a vertical shaft? Find something with a straight horizontal shaft.

Some engines have weird output shafts. For example I think generators have strange output shafts that aren’t straight or something.

Off-season snowblowers with good engines might be found for around $50.

 

[bob58o]

What’s the cheapest braking system if you can fabricate it…

Maybe a “Scrub Brake”?

Not the best option, but GoKarts brakes are often overrated. LOL. I figure if I can turn, stopping is less important. LOL. Kidding… safety is important.

 

[bob58o]

A metal bed frame is a better option than plywood for a gokart frame in my opinion.

 

[bob58o]

Also I didn’t see you mention a rear sprocket.
Unless it is attached to the set of wheels you already own (as a drive wheel would be set up on a single drive wheel kart).

You need a rear sprocket to attach by chain to the clutch (or gearbox output sprocket if using a gearbox).

If the axle spins (as it would with a live axle kart), the sprocket needs to attach to the axle with some sort of hub/carrier.

Some sprockets are made with the carrier/hub already attached. I think of Martin sprockets as having the hub already welded on, but that’s probably not correct.

 

[panchothedog]

Do you already have tires and wheels for the rear axle? The diameter of the tire will be the determining factor of using a centrifugal clutch or a torque converter. Neither one is prohibitively expensive. As others have already pointed out, you don't need a 400 cc engine. A 6 hp. 212cc engine will work fine. And please DO NOT BUILD IT OUT OF WOOD. Not of any kind.

 

[kaylsy]

Wait sorry guys i messed up we actually are using a metal frame!!

 

[kaylsy]

Also I didn’t see you mention a rear sprocket.
Unless it is attached to the set of wheels you already own (as a drive wheel would be set up on a single drive wheel kart).

You need a rear sprocket to attach by chain to the clutch (or gearbox output sprocket if using a gearbox).

If the axle spins (as it would with a live axle kart), the sprocket needs to attach to the axle with some sort of hub/carrier.

Some sprockets are made with the carrier/hub already attached. I think of Martin sprockets as having the hub already welded on, but that’s probably not correct.



View attachment 149800View attachment 149801View attachment 149802

YOU ARE SO HELPFUL!! How many sprockets do you need? Is it only one? And how do you know if you need a torque converter or a centrifugal clutch? Is it only one or the other?

 

[ezcome-ezgo]

Slow down and think about this. The engine has an add-on device that transfers the power to a chain, either a centrifugal clutch or a torque converter (preferred). From here the chain transfers the power to the wheel (one wheel drive) or axle (two wheel drive), depending on your set-up. On the wheel or axle is a sprocket for the chain to transfer power through. The difference in the size of the sprocket on the device on the engine vs. the size of the sprocket on the wheel/axle is your gear ratio. A good target for that ratio is 6 to 1, meaning for every tooth on the clutch/TC, there are 6 teeth on the wheel/axle sprocket. Don't overthink this, you may get confused.

 

[bob58o]

Ya what he said. 2 sprockets minimum.
10T in front (on clutch/cvt) 60T in the back (axle).

Or 12T on front and 72T on back.

If the rear tires (assuming rear wheel drive) are 16” or over… a CVT is best.

If rear tires are under 16” a centrifugal clutch might work depending on how heavy this kart will be with people in it.

Did you show us or tell us about the wheels and tires yet? The diameter of the tire is important to help you get the sprockets correct.

 

[bob58o]

Here are some scribbles and a photo if confused on how a CVT set up goes.

The CVT option only works with the smaller engine because of the budget… I think.

30 series work on 3/4” shaft engines and complete set with that nice backplate are cheap.

40 series are needed with 1”shaft engines and are more expensive. Perhaps prohibiting expensive. I’m not sure $400 works with a $200 400cc engine

 

[bob58o]

$55 for 30 series kit.

 

[bob58o]

Not familiar with this kit…
But similar style kit for a 420cc cost 3x as much

 

[kaylsy]

Not familiar with this kit…
But similar style kit for a 420cc cost 3x as much
View attachment 149842

Thanks! We just measured our wheel diameter and they are 14". What is a CVT set up? I looked it up and vaguely understand it. Is it better than the other set ups? Does our item list change? Here's the engine we are getting instead: https://www.harborfreight.com/65-hp-212cc-ohv-horizontal-shaft-gas-engine-epa-69730.html

And our current complete item list:
*Engine

• 3/4” 160-212cc engines
• https://www.harborfreight.com/65-hp-212cc-ohv-horizontal-shaft-gas-engine-epa-69730.html
• $149.99

*Rear axle
*2 Sprocket

• sprocket needs to attach to the axle with some sort of hub/carrier
• If the axle spins (as it would with a live axle kart), the sprocket needs to attach to the axle with some sort of hub/carrier
• Some sprockets are made with the carrier/hub already attached
• 6 to 1, meaning for every tooth on the clutch/TC, there are 6 teeth on the wheel/axle sprocket
• 10T in front (on clutch/cvt) 60T in the back (axle) Or 12T on front and 72T on back
• https://www.amazon.com/Sprocket-Keyway-Hardware-Predator-Buggies/dp/B0CM8NTDDB?th=1
• $33.99 (x2)

*Gas Pedal\ Brake Pedal
- makeable
* Steering Wheel
- makeable
* Chain for engine
- own
* Brake line
- need
*Torque Converter OR Centrifugal Clutch\
https://www.amazon.com/Mophorn-Conv...-lpcontext&ref_=fplfs&smid=ATVPDKIKX0DER&th=1
*Automatic Gear Shifter
- need
* Steering Shaft
- need
*Shocks/Coilovers
- need
*Disc Brakes
- need
*Twist Throttle or Gas Pedal
*Brake cables
*Steering linkage
*Pedal assemblies
- need all above
*Spindles
- https://www.bmikarts.com/Complete-Spindle-Set--4-12-x-58-_p_1319.html
*Tie rods
- https://www.bmikarts.com/516-24-Female-Tie-Rod-End_p_1475.html
*Bearings
- neeed



Would this torque converter work for that engine?
- https://www.amazon.com/BLACKHORSE-RACING-Torque-Converter-Driven-Asymmetric/dp/B07N7VBQSV?th=1

Also... what can you tell us about bearings?
Thank you so much for your help!!!!!!!!!!!!!!!!!! We are just kids and no one is helping us

 

[ezcome-ezgo]

 

[ezcome-ezgo]

The "Vevor" product that Bob illustrated includes the backing plate, which is recommended for your application. Not endorsing Vevor.

 

[Karttekk]

One thing to keep in mind is the bolt thread pitch on these Chinese torque converter kits. Most if not all 6.5 HP small engines have 24 pitch threads in the crankshafts and in the engine side covers. The last kart I sold had one of these installed on it but it was rusted and worn out. I went to install a new drive clutch and the torque converter cover plate along with the Comet driven the seller included when I bought it from him but the factory 24 pitch bolts wouldn't thread in. He "forced" the 18 thread pitch bolts included in the kit into the engine side cover and crankshaft. I had to chase the threads with a 24 pitch tap to clean them up and allow the correct bolts to be installed. When you go to install one of these and the supplied bolts start to thread in but bind up, stop and check the bolt threads with the factory originals or chance damaging the threads.

 

[Denny]

Only Use Genuine Comet Belts!!!