3 boys and a dad... all the tools, first go-kart

[bdruff]

We just moved out to the country and now have several acres for my boys to ride.

I thought it would be a fun project for us to build a go kart.

I think I have access to all the tools I would need.
Torch (Might need to be refilled)
Arc welder and wire welder
12" metal chop saw
grinders...

I sourced the frame, front axle, rear axle, and 11hp Honda engine.

The axles are off Honda quads and I'm picking up wheels and tires today.

I've never built anything like this before. I've worked on cars my whole life and have built a house but I've never fabricated with metal and I only have a limited amount of welding experience.

Anyway, I'll be reading all the forums I can for the next week or so.

My first issues are mounting the axles.

 

[2SlickNick]

Welcome. It looks like a cool project.
At least working with metal of you make a boo-boo you can always cut, grind, and weld again.
Measure your rear axle diameter and order the appropriate size bearings, hangers, and flangettes.
It looks like your frame is pretty plumb. So that should help when measuring axle hanger location.
Try to put the axle somewhere close to the stock location.

Others will chime in.

Oh and Welcome!

 

[DirtyDamage]

The frame almost looks like a side by side or a utv. Kinda interesting

 

[RobertD]

 

[bdruff]

Thanks! The rear axle has mounting brackets on it. There is a brake built into it and the axle spins freely inside the housing. I'll need to fabricate something to mount the housing to the frame but I don't think I'll need hangers and a bearing... or am I mistaken?

The rear axles with the tires on only give me about 20 inches from the inside of one rear tire to the other. The frame is 26" wide which means I need to mount the rear tires behind the frame or raise the frame up above the tires.

The same is true for the front. I'll need to mount the front axle so that the tires are either in front of the existing frame or beneath it.

Another option is to raise the back and then extend the front.

This will be a journal for me too so forgive the many posts... Some of the questions are meant for me to search for...

It seems like both of these would be easier than modifying the frame.

---------- Post added at 07:26 PM ---------- Previous post was at 07:24 PM ----------

I thought the frame looked cool too, thanks. I would like to put a flatbed platform above the engine kinda like a flat bed truck.

---------- Post added at 07:43 PM ---------- Previous post was at 07:26 PM ----------

I'm reading now... but another issue is getting the power to the wheels. I have a Honda 11hp with a 1 inch shaft.

I assume I'll need a centrifugal clutch but what about sprocket sizes? I have a couple larger sprockets laying around but I don't know how to figure out gear ratio.

The back tires are about 20" in diameter, give or take. I don't remember.

 

[chancer]

Welcome you have a cool project there. Sounds like great fun for you and the kids and the property.
But I think you are way off on the Axle ideas. Scrap that hona axle.
Your cart has bearing hangars in it. You need to get a set of "bearing flanges" they will bolt up to the mounts. Then get a 1" about 34 or 36 incch axle and mount it in the stock location.
That is a start.
Here is link to many go kart parts suppliers: http://www.diygokarts.com/vb/showthread.php?t=1180

 

[bdruff]

Bearing flanges with a wider axle does sound like a simple solution to my problem.

Hopefully I can trade what I have. I got the axle from a motorcycle salvage yard. Not sure what their policy is.

---------- Post added at 09:34 PM ---------- Previous post was at 09:21 PM ----------

What about the front axle....am I way off trying to use what I have? It has brakes built into the hub which I thought was cool.

I'll still need to extend the front end (or put the front axle below the frame) because it is not wide enough to sit outside the frame.

 

[bdruff]

Torque converter

Much to read...what a great site!

So with them driving mostly on dirt and on rough terrain, it looks like a torque converter is the way to go.

Wonder if I could get something at the motorcycle salvage yard or is that something I will probably want to buy new.

---------- Post added at 11:29 PM ---------- Previous post was at 10:41 PM ----------

The idea is to get the kart running and then let my boys spend the next several years working on it, modifying it, and upgrading it. Maybe they could even duplicate a few and sell them.

I have about $350 in it so far. Everything has been sourced as used. I prefer using what I have, even if it needs to be modified, over buying new.

I like the idea of changing the rear axle from what I have to using the bearings with the existing mounts. Sure wish I knew before I bought the rear axle. I need it wider anyway and if I go back to the salvage yard, they will probably trade me. The spindle hubs don't match my wheels either. I was going to drill new holes, but maybe I can match the correct spindle hubs to the wheels I got.

For power transfer, I'm looking for a torque converter.

I have a couple off brand quads from China that are just rotting. I'm wondering if I can use the chain and/or sprocket from one of those. I plan on using the lights. Then I thought, could I use the transmission? Maybe there is something there I could use. It is an automatic with no clutch so it's either centrifugal or has a torque converter.

I appreciate the advice. I'm using this thread as a journal too so some of the posts may seem repetitive. Hope that's OK.

Hopefully, some other ambitious builder can learn from a few of our mistakes.

 

[bdruff]

exchanged the rear end

I think I did good in my exchange for a rear axle... I don't know if the disc brake can be salvaged but there is a sprocket and the bearing flanges I think Chancer was talking about.

Hopefully everything comes apart easily. The brake and sprocket have to be moved but it should work perfectly.

It's wider than I needed, but that's better than too narrow which I was worried about.

The tires are 20 x 8

I'm still hoping to be able to use the front axle. It would be cool to have front brakes.

 

[bdruff]

Here are some shots of the front end with the tires

 

[OzFab]

So with them driving mostly on dirt and on rough terrain, it looks like a torque converter is the way to go.

Wonder if I could get something at the motorcycle salvage yard or is that something I will probably want to buy new.

New is always the best way to go but, a good used unit could work; try posting in our sale or trade section...

Before doing that, you need to figure out what engine you are using; up to (but not including) 8hp industrial engines have a 3/4" shaft & use a 30 series TC, 8hp & above have a 1" shaft, requiring a 40 series TC...

I have a couple off brand quads from China that are just rotting. I'm wondering if I can use the chain and/or sprocket from one of those. I plan on using the lights. Then I thought, could I use the transmission? Maybe there is something there I could use. It is an automatic with no clutch so it's either centrifugal or has a torque converter.

Quads/ATVs usually use 50 series chain (5/8" from pin to pin) whereas karts use either #35 (3/8" from pin to pin) or #40/41 chains (1/2" from pin to pin)

If you can get the engine running, there's no reason you can't transplant the entire drive train into the kart; be aware, that will involve some fabrication work...

 

[bdruff]

Thank you...I sourced a honda 11hp for the engine. It has a 1 inch shaft.

Lots of info about torque converters. Looks like there is one on ebay for about $76 that will work with my engine. I'm still a little unsure how to set it up.

I looked here in town but the only go kart shop is closed until the new year.

The sprocket has 45 teeth but the last post helped a lot. I was confused about the different types of chains.

I bought 2 of those quads new for almost $1,700...I might be able to get 1 of them going by combining parts but they are horrible and constantly broke.

 

[OzFab]

I bought 2 of those quads new for almost $1,700...I might be able to get 1 of them going by combining parts but they are horrible and constantly broke.

That's Chinese engineering for you

 

[bdruff]

A few days into the build... Here is the progress and general idea of the finished buggy. Front end is going together good. Still have a few braces and welds to do. I put it together with bolts that I have here at the house but I'll replace most of them with matching bolts that are better sized.

I don't have a solid plan for the steering yet. Is there a perfect angle for the tie rods or should they be mostly horizontal? I don't really know how it will work yet. That is the next step so I'll be reading about steering...

Also, there is an on/off switch on the engine. The yellow wire has been pulled from the case (Circled in red) and the switch does not work. To kill the engine, you can touch the yellow wire tip to the engine case where it came out and it will kill the engine.

I can take the engine apart and fix it but I'd rather use that as a kill switch up front. Can I just run a wire off that yellow wire to a button up front that grounds it?

Thanks for the help if anyone has suggestions.

I'll post pictures and updates as it comes along.

 

[chancer]

That yellow wire will kill the engine (once bolted to the kart) when touched to any Ground. So you can wire it to a switch accessable from the driver seat to kill the engine.

 

[bdruff]

Want to figure out gearing also...

I have to buy a torque converter... The axle sprocket that I have is 45 tooth and I'm 90% sure it's 50 series... The rear tires are 20 inch quad tires.

With the Engine I have (Honda gx340 11hp)... What should I look for? It has a 1 inch crankshaft if that matters.

I saw one thread that said 30mph is a goal with 18 inch tires. One person suggested using a 10 tooth sprocket on the jackshaft with a 60 tooth on the axle #40 chain.

I don't have a chain so if I need to get a different sprocket, I can, or can I get a chain to match my sprocket?

The torque converters I'm looking at, look like they are belt driven... So does that mean that I need a jackshaft?

I don't really understand how the torque converter will transfer power to the axle...I'm reading about Jackshafts but don't completely understand them and whether I will need one.

This is my first go kart build so everything is new.

thanks again

 

[bdruff]

something like this probably

 

[bdruff]

Copied from another thread...

Went for the first spin yesterday....it runs like a dream!
A bit slower than I hoped for but faster than expected. Opted for a 1:7.6 gear ratio, a good balance of torque & speed.. the result is loads of torque and bit low on the speed..
Running a 10 tooth on the clutch and a 47 on the secondary, then a 13 down to a final 32 on the axle. I opted for the smaller final gear on the axle to give me better ground clearance. Ill run the buggy as it is for now but will install a 32 tooth on the secondary.

He says he has a 47 on the secondary now but wants to change to a 32 tooth... he has 18 inch tires if I remember right.

He has a 9hp engine

 

[bdruff]

If this thread is better suited for the build section, feel free to move it. I'm answering a lot of my own questions as I go but this is a good way to keep track of all the info as I learn it.

 

[Tonyzsi]

Personally I like seeing what other people are doing. I'm not sure I'll ever buy a welder and get this advanced, but maybe I'll make small modifications to the kart I have. Keep the pictures and details coming.