Kettcar 50cc Minimoto engine

[Kettcar]

Hi I'm in the middle of converting a original pedal Kettcar go-kart in to a 50cc one. Just a little stuck on how to attach the sprocket onto the axle, does it require welding or bolts. If anyone has an answer would be much appreciated.

Many Thanks Chris

 

[landuse]

Post up some pics of what you have. There are many ways to attach the sprocket though. You can either weld it on, but then you will never be able to change it if you want to regear. You can also cut a keyway into your axel and sprocket and use a key to attach the sprocket. Depending on what your sprocket looks like, you can also have some set screws to give extra hold. Here is what I did for a jackshaft of mine. I had to have keyways cut and setscrews put in.

 

[Kettcar]

Pictures Of the Go Kart and axle here, do not have access to to welding, thinking about bolting sprocket to existing one.

https://skydrive.live.com/?cid=51E43C7CC12B7AD3&id=51E43C7CC12B7AD3%21106&sc=photos[/URL]

 

[landuse]

I'm sorry, but that link doesn't work for me. Try post pics here by replying, going to 'advanced' and then 'managing attachments'

 

[Kettcar]

Ahhhh thanks for tip here pics

 

[landuse]

You could bolt that larger sprocket onto the smaller one. The only problem is that you are going to have to get it dead center with the axle, and that might be a problem. If you don't, the sprocket is going to move 'up and down' as the axle turns. It looks like you might have room enough to drill holes through the smaller sprocket for the larger to bolt onto.

You could also get a hub that the sprocket could bolt onto. Something like THIS. It depends on the diameter of your axle, as well as if it is keyed or not. You might have to get a keyway cut.

 

[Kettcar]

Thanks for reply, about the sprocket holder does that bolt onto the axle or does it require welding.

 

[landuse]

Thanks for reply, about the sprocket holder does that bolt onto the axle or does it require welding.

It doesn't bolt on. It uses a key and a keyway on your axle. The key is a little bit of square metal rod, that fits between your axle and the sprocket holder. The sprocket holder and the axle have a keyway (a groove machined in it). The key then fits between the 2, holding them together. You can see this in the pic that I uploaded.

The sprocket holder also has set screws in the side which get tightened onto the axle. All these things keep it fixed on the axle. The only things you must look out for are 1) Is your axle the same diameter as the sprocket holder, or can you get one that is. 2) Are the bolt holes the same as my sprocket holes. 3) will you need to cut a keyway in your axle.

You could always just weld the holder onto the axle if that would be more practical for you. It would save all the extra hassle of keys and keyways if you don't have them.

What is your gearing going to be like? Have you thought about the different gearing options that are available? Do you know what that sprocket you have is going to do for your performance?

Why I am asking is that I don't want you putting this sprocket on, and you find that your 50cc engine is never going to push you around with a sprocket that big. It looks like it is about a 70tooth sprocket.

 

[Kettcar]

Still working on it, almost done

 

[landuse]

That’s looking good. What did you decide to do with the rear sprocket?

Just one or two points. You should make some sort of chain guard, because that chain is way too open and close to your legs to be safe. I am also a little concerned that all the weight is going to be on the back of the kart with your seat so far back. The recommendation (or so I have heard) distribution is 40% on the front half and 60% on the back. Steering gets negatively affected if the kart is too light in the front. This is something you are going to have to see when you eventually get to drive it.

I was just also wondering if that handle by the wheel is for your brakes or throttle? How would you push it? It looks a bit difficult to do with your foot.

Otherwise it is looking sweet!!

 

[SFort]

Zombie thread revival for my first post... sorry.

I am looking to do exactly as above with a motor I scored. If Kettcar is still around here I'd love to head how it went, anything you'd do differently etc.

I'm particularly interested in gearing. I am reasonably handy but come from a car background. All this sprocket stuff is new to me. Would 6:1 be suitable?

 

[landuse]

Zombie thread revival for my first post... sorry.

I am looking to do exactly as above with a motor I scored. If Kettcar is still around here I'd love to head how it went, anything you'd do differently etc.

I'm particularly interested in gearing. I am reasonably handy but come from a car background. All this sprocket stuff is new to me. Would 6:1 be suitable?

Kettcar hasn't been on the site for more than a year. Start a thread of your own, referencing this thread and ask away. A 6:1 should be fine depending on engine size as well as tyre size

 

[anderkart]

Zombie thread revival for my first post... sorry.

I am looking to do exactly as above with a motor I scored. If Kettcar is still around here I'd love to head how it went, anything you'd do differently etc.

You could try sending Kettcar a private massage at this link: http://www.diygokarts.com/vb/private.php?do=newpm&u=9701

 

[SFort]

Thanks for the responses, will do.

 

[evant]

Kart

Making one of these is quite simple after, ill upload pics in a while i must find them first, if you have a mini motor bike lying around its so easy, use the steering off the bike, connect the throttle to the brake lever and the back brakes to the other, then shape the bars into a custom steering wheel, wield the Big cog onto the existing one and the disc brake to the back axle, The petrol tank can be mounted to the back of the seat if you make a cage for it out of wire mesh, overall i tought this was the easiest project ive done yet

 

[landuse]

Making one of these is quite simple after, ill upload pics in a while i must find them first, if you have a mini motor bike lying around its so easy, use the steering off the bike, connect the throttle to the brake lever and the back brakes to the other, then shape the bars into a custom steering wheel, wield the Big cog onto the existing one and the disc brake to the back axle, The petrol tank can be mounted to the back of the seat if you make a cage for it out of wire mesh, overall i tought this was the easiest project ive done yet

When you post up how its done, start your own thread. Don't do it here