[Kartbuilding] Go kart Questions

Stephen Burke sburke at burkesys.com
Thu Dec 7 09:59:55 GMT 2006

Hi Austin,

Thanks for the photos - they really help explain whats happenning. I have 
edited one of the photos and added in text etc. pointing out how the cable 
will operate the throttle. The digram of the throttle can be found at:

The above diagram should help deciding where to place the cable. A brake 
cable off a bycycle etc. will suffice. A brake cable on a bycycle is made 
up of 2 parts - the inner steel brake cable (stranded) and the outer 
sheathing (which the inner cable passes inside). The steel brake cable 
*must* be pulled out from inside the outer sheathing. If you look at a 
setup for the brakes on an old bycycle - you will realise how it works.

I saw also your photos of the rear axle. They look fine - and a are a very 
good setup. Those rear axle bearings is exaclty what I used on my old 
racing kart. See: 

However - instead of using the steel plates (in gray on your photos) - 
I made a rectangular box/enclosure for the bearing plates. See:
(Also note that you can look at the 3d model of the racing kart at: 

Anyways - with this rectangular fashioned piece of steel the sideway 
movement of the rear axle is limited.

Similarly, - you could simply weld the steel plates provided in your 
kit (as you mentioned) - and simply weld on ribs/reinforcement pieces to strengthen it to the 
chassis. As I mentioned before - be careful not to make a hole (with the 
welder) in the chassis - as this would weaken it significantly.

As for the chassis you have made so far - it looks good - its shaping up. 
Bending the steel tubing is far from easy - as you have found! It seems 
ok. Just make sure that all the joints are securely welded. If you send on 
some more pictures of the kart - I will put a special page on the 
www.kartbuilding.net website for your kart.

Best of Luck,

On Wed, 6 Dec 2006, Austin Tsai wrote:
> Hey Stephen,
> Thanks for your quick reply! I was actually suprised you responded to my 
> questions so quickly. Thanks for the run down and links to the response to my 
> questions.
> To clarify, I do have the adjusting lever for the throttle. I have a few 
> pictures of it here:
> http://img.photobucket.com/albums/v130/SuiJai/Xanga%20shit/Photo-0021.jpg
> http://img.photobucket.com/albums/v130/SuiJai/Xanga%20shit/Photo-0020.jpg
> http://img.photobucket.com/albums/v130/SuiJai/Xanga%20shit/Photo-0019.jpg
> http://img.photobucket.com/albums/v130/SuiJai/Xanga%20shit/Photo-0017.jpg
> http://img.photobucket.com/albums/v130/SuiJai/Xanga%20shit/Photo-0016.jpg
> http://img.photobucket.com/albums/v130/SuiJai/Xanga%20shit/Photo-0015.jpg
> Sorry for the blurry pictures. I had to take them from a camera phone as I 
> didnt want my digital camera stolen from school. I'm still not sure how I can 
> hook up a brake cable to control this lever, or maybe that's because I'm not 
> too sure how a brake cable connects. I know for brakes it pulls the cable and 
> uses a lever to squeeze the brake pads together. How does it work in this 
> case? Maybe if you could draw a diagram that would help me out a whole lot.
> http://img.photobucket.com/albums/v130/SuiJai/Xanga%20shit/Liveaxleassembly.jpg
> Here is a picture of the axle assembly that I picked up. My plan was to 
> "T-weld" the two dark grey peices onto the frame that I built. My question is 
> though, Do I have to reinforce these two peices at all? It seems awfully thin 
> to support itself with 5 hp running it. I know I seem in a little bit of a 
> rush (Parts have not arrived yet) but I like to plan ahead on how to do 
> things.
> I got a few snaps of my frame which can be seen here:
> http://img.photobucket.com/albums/v130/SuiJai/Xanga%20shit/Photo-0022.jpg
> http://img.photobucket.com/albums/v130/SuiJai/Xanga%20shit/Photo-0023.jpg
> What do you think? I copied a FIAA Tony Kart frame that I found off the web. 
> It was 1:10 scale so I basically measured all the angles and cut it to the 
> real scale. I have to say though, bending tubing manually is quite tedious 
> work. It was hard to get the 3 front bends to be precise to the scale drawing 
> so they are a bit off. The front is still missing the front axle peices as 
> well as a foot support. Hopefully my parts will arrive in this week and I can 
> get a bit more progress done.
> Thanks for all the help! I really appreciate you taking time out to answer my 
> questions.
> Austin Tsai
>> From: Stephen Burke <sburke at burkesys.com>
>> To: Austin Tsai <tsai_austin at hotmail.com>
>> CC: kartbuilding at lists.burkesys.com
>> Subject: Re: Go kart Questions
>> Date: Sat, 2 Dec 2006 14:39:45 +0000 (GMT)
>> Hi Austin,
>> Im glad you found the www.kartbuilding.net website useful, and that you 
>> have decided to build a kart yourself. It does have a lot of the info 
>> needed to build a go-kart of any type. Onto answering your questions:
>> #1. The Throttle on your Honda GC160 engine.
>> I done some looking there and have found some nice diagrams/info about your 
>> engine:
>> - Blueprint for your engine & drive shaft:
>> http://www.tulsaenginewarehouse.com/catalog/honda/specs/gc160/
>> - General Info:
>> http://www.trupower.com/honda/gc160.htm
>> Actually - here is the User Manual for that Honda GC160 engine!!:
>> http://www.honda-engines.com/Engines_owners_manuals/ownersmanuals/31Z8A000.pdf
>> It shows you all you need to know about the throttle.
>> Does yours have a variable throttle lever? (as on page 2 of above manual?) 
>> If so - all you have to do is connect up a small cable (e.g. brake cable 
>> off a bycycle etc. to operate this throttle lever. Bycycle shops will give 
>> you extra long brake cables and a reel of brake sheething which you can cut 
>> to length.
>> If you dont have a throttle lever on your engine, you have to look at the 
>> carburattor itself. There will be a small lever which links up to the 
>> "butterfly valve". I couldn't get a clear picture of this valve from the 
>> above manual. Here is a photo of this lever on a carburattor of mine:
>> (valve closed - engine idling):
>> http://www.kartbuilding.net/gallery/v/Kart_Clearance_and_Memories/DSC01242.JPG.html
>> (valve open - engine turning fast):
>> http://www.kartbuilding.net/gallery/v/Kart_Clearance_and_Memories/DSC01243.JPG.html
>> Notice too the screw on the above lever - this is to adjust the idling 
>> speed. You need to firstly - find this lever on your engine (there should 
>> be a spring attached to it) (you might have to take off the aircleaner to 
>> see it fully). Run the engine - turn this lever manually and see if the 
>> engine speeds up when you pull on the spring. If this works - all you have 
>> to do then is to connect up a cable to operate this small lever. It should 
>> work fine.
>> The reason a throttle lever is not on all engines - is because they dont 
>> need to go slow/fast - just run at the same speed. But ALL engines can be 
>> made to go fast/slow by adjusting this throttle adjuster lever connected to 
>> the butterfly valve which limits the petrol filled air from going into the 
>> engine.
>> #2 - Axle Bearings
>> There are a few types of axle bearings available. As you said - you wont 
>> really know until you have it in front of you.
>> The main thing to note: DO NOT DRILL HOLES IN THE CHASSIS <-> this will 
>> only weaken the chassis causing it to break/bend. WELD ON A LUG or SUPPORT 
>> BRACKET onto the chassis FIRST - then bolt the bearing housing to this 
>> This picture shows the above -> 
>> http://www.kartbuilding.net/Freeplans/images/pillowrunner.jpg
>> (or the page for axles is on http://www.kartbuilding.net/Freeplans/axle.htm 
>> )
>> You could also have a Vertical Bearing mounting plate - in which case you 
>> have to weld a vertical plate to your chassis - and then bolt your axle 
>> bearing to this instead. See: 
>> http://www.kartbuilding.net/racingkart/Old_Racing_Kart/rearaxle.htm
>> Just make sure that the axle rotates freely before welding/bolting the axle 
>> mountings onto the chassis. ALSO - make sure that the rear axle and its 
>> wheels are parallel to the front stub axles (i.e. distance from rear left 
>> wheel to front left is the same distance from rear right to front right 
>> wheel)- other wise your tyres will wear very fast.
>> Anyways - if you take any photos send them on and I will put them on the 
>> www.kartbuilding.net website.
>> Best of Luck,
>> Steve
>> On Fri, 1 Dec 2006, Austin Tsai wrote:
>>> Hi there,
>>> First off, I'd like to say how wonderful your site is. I recently got into 
>>> an automotive class in school and thats when I decided to build a go-kart 
>>> and stopped by your site. Very nice layout, and tonnes of info!
>>> Anyways, I was wondering how I could get my engine to drive by a wire. I 
>>> know there are throttle kits out there, but I'm not too sure how they hook 
>>> up. Right now I have a Honda GC160 (Horizontal shaft engine) that I have 
>>> rebuilt, but the only problem is to get it to drive by a pedal speed. Any 
>>> ideas on how I can accomplish this?
>>> Second question I have is that I bought an axle bearing kit (It hasnt 
>>> arrived yet so I might be jumping the gun a little here), and I was 
>>> wondering how you can attach it? I know the kit comes with the bearings as 
>>> well as a bracket, so my guess right now is to just weld the bracket onto 
>>> t he frame, correct? I see a lot of professional go-karts have a different 
>>> type of axle bearing so I havent been able to find what I want.
>>> Thanks for all your help in advance, keep up the awesome work!
>>> Austin Tsai
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