Aussie kart "It doesn't have to be perfect"

[rubberducky]

Sitting around the table post christmas festivities we realised (brother-in law and i... that we needed a project... something substantial. In our favour access to my parents 40 acre property to which there is plently of room for some off road action.

It was decided we need something motorised... something cheap... something fun... and something that can handle off road!

The project begins.. an offroad kart was the calling.

It began with the purchase of an engine. A 5.5hp horizontal shaft engine from deals direct ~ $179. AU

We quickly mocked up a basic frame with the stick welder and sat the engine on for a test visual, with some trolly wheels we had.

We decided the running gear for this kart would be above us to manufacture so we shelled out for: bearings, sprocket (64 tooth), sprocket hub, chain, and a centrifugal clutch(12 tooth).

Then we test fitted a centrifugal clutch to the engine shaft ..... shaft was 2mm too big to fit in the clutch ..wtf. Easily fixed we took it to a kart dealer and had it machined to fit. Nice and snug now.

While the shaft was out we decided it was time to take the govenor out as well.

We also decided to cut the low oil sensor line but have decided to leave it in at this stage until we get more confident about our mods

There will be more pictures to come.

We have done a few changes to the main chassis and will take some pics of that soon.

But so you know this is an offroad kart so there will be full independant front suspension (of sorts) and rear suspenion to suit.

For now

 

[modelengineer]

That looks like the start of a great project!

Where in Australia are you?

 

[r_chez_08]

sweet....
what does the gov do:arf:

 

[jr dragster T]

The governer limits the maximum RPM the engine can run at. Most utility engine's are rated at 3600 + - 100 RPM or so.

 

[Russ2251]

As the name suggests. Governs the speed.

 

[r_chez_08]

oh, lol. my engines rated 4000rpm
is it a good idea to remove it?

 

[jr dragster T]

Interesting that this Honda engine utilizes a nylon cam. rchez 08 are you sure stock governed speed is 4000?

 

[Russ2251]

Interesting that this Honda engine utilizes a nylon cam.

Get used to it. Most are now. Nothing wrong with them.

 

[jr dragster T]

Lol I wasnt saying anything bad about it. Lol you could like plasti-weld over the lobes and sand it and make a new cam pretty easily.

 

[r_chez_08]

Interesting that this Honda engine utilizes a nylon cam. rchez 08 are you sure stock governed speed is 4000?

thats what it says: max output/ speed 4.8kw/ 4000rpm

 

[jr dragster T]

So if you where to put a steel inplace of the nylon cam would you need new tappet's? Like are the tappet's desihned only for plastic to metel?

 

[Russ2251]

So if you where to put a steel inplace of the nylon cam would you need new tappet's? Like are the tappet's desihned only for plastic to metel?

Unknown to me. Probably no different as tappets still have to rap into valve stems. If softer, would mushroom in short order.

 

[rubberducky]

That looks like the start of a great project!

Where in Australia are you?

Thanks. It's heaps of fun building this thing.

Were in Brisbane, Queensland.

Going to upload some pictures of our front suspension and steering column support tonight.

 

[BradenM]

Great project mate
Geelong, Victoria.

 

[rubberducky]

Front Suspension arrangement

Hey guys, just put together a front suspension arrangement. Managed to get away with some shocks off a mountain bike we found in a skip bin. They have adjustable knobs on the top which will help us set the resistance in testing. The other key was to use some ball joints on the bottom triangle arm... we went a triangle so it can resist horizantal impact as it occurs.

It seems to work pretty well.. we may need to brace it up a little more for some strength..

You can also see that we are starting to think a little bit about how our steering will fit in.... and we found an old school chair which will be welded into place soon...

Next on the kart build agenda will be some steering spindles and tie rods and maybe even attaching the front wheels!

 

[modelengineer]

Looks good, but you should join the top of those shock towers for strength. Just where the top of the shocks are, join with a piece of pipe/tube.

Keep up the good work,
Andrew (in Sydney)

 

[rubberducky]

Yeah.. we definately join at the top.. did a little bit of load testing tonight and i can see some movement.. also might brace down to the front of the frame...

 

[r_chez_08]

lovin' the shocks!

 

[Kaptain Krunch]

nice use of old bike's, but will those shocks be able to handle the weight of a go kart? I've bottomed out my bike shocks plenty of times going maybe 30 or 40 and hitting some rocks or ruts.

 

[rubberducky]

nice use of old bike's, but will those shocks be able to handle the weight of a go kart? I've bottomed out my bike shocks plenty of times going maybe 30 or 40 and hitting some rocks or ruts.

Good question Krunch... as you can see tht we have naturally say the triangles at a lower position than the main frame... such that a bottom out of the shocks will mean the triangles will be horizontal...