Sprockets!!!!!

[Shaun.]

So I'm building a kart
I'll be honest I don't know what the frame is. I picked it up super cheap
How ever, I'm having a hard time finding a sprocket that'll work.

I'm fitting my kart with a Ninja 250R engine from 2007.
Which means the chain size is going to be a #520
But the issue I'm facing is finding a sprocket hub and sprocket that will work.
The axle is 1" thick
So I'll need a 1" bore sprocket with 520 chain. I need something around 46-47-48 tooth because of the size of the kart.
And there's no keyway on this axle so I'll have to weld it on.

Can you guys help?
I'm going Absoutly crazy trying to find this
And if you guys know of any tensioner a that would be great thanks!
This is my kart!
https://imgur.com/a/AgN0G

 

[Iron John]

Nice kart!

I would simply buy a sprocket that fits your keyway and axle, and bolt or weld a 520 sprocket to it.

Here's one I once made:

 

[OzFab]

NEVER, EVER, EVER, EVER, EVER, EVER, EVER WELD ANYTHING TO AN AXLE! Not only does it damage the axle (causes a weak point & possible distortion) it makes it almost impossible to disassemble the axle in the future...

What you need to do is along the lines of what Iron John suggested, find a suitable sprocket & a suitable hub then find a way to join the two together; simply bolting the two together should work; just be 110% sure the sprocket is centred on the hub...

 

[Bwdeaton]

There should be an existing sprocket on the axle. You will have to weld or bolt a 520 sprocket to the existing one to get it mounted because, as others pointed out, welding to an axle damages the temper and can weaken it.

I've done a few ninja 250 swaps into quads, and I'll say that they make quite a bit of power for their size. Got 80mph on a death trap 4 wheeler. Also their rather cheap for parts.
Aim for at least 3:1 reduction for this project, don't go any lower. Higher reduction will get you more torque and make it easier to operate the clutch.


Sent from my iPhone using Tapatalk

 

[landuse]

Never ever weld anything to the axle. Period!

 

[itsid]

Hmm the original Ninja sprocket has a 6 on 130mm bhc.. with 10.5mm boltholes (for 10mm bolts)
a std go Kart Sprocket hub has a 6 on 5.25" bhc (that's 133.35 mm) for 1/4" bolts ( 6.35 mm)

So the "outside" circle is 140.5 on the sprocket and 139.7 on the hub

those two are close enough together that you can offset widen the threads on std go Kart Sprockethub to accept a std motorcycle 6on130 sprocket with 10mm bolts

I doubt the center ring will match but I'd think that can be dealt with too

here are the bolt hole circles on top of each other ..

see that you can enlarge the red holes in the hub to make them match the blue ones in the sprocket?



But there's an easier way.. a MUCH easier way:
contact JT Sprockets:
http://www.jtsprockets.com/contact

Ask them for a to provide you with a 420 sprocket for your z-13 splined shaft
that way you can just use any #40 Sprocket and that is very common on go karts (#40 NOT #41!!) pitch, roller diameter and width are identical.


'sid