[Kartbuilding] Questions concerning go carts

[Stephen Burke]

Mike,

On the chainsaw engine - there should be an bell shaped housing - onto 
which the chainsaw chain attaches. See middle object:
http://www.kartbuilding.net/gallery/v/Kart_Clearance_and_Memories/DSC01283.JPG.html
and
http://www.kartbuilding.net/gallery/v/Kart_Clearance_and_Memories/DSC01038.JPG.html
and
http://www.kartbuilding.net/gallery/v/Kart_Clearance_and_Memories/DSC01036.JPG.html
You can see the star shaped existing sprocket which drives the cutting 
chain on the chainsaw. You will have to weld your normal sprocket off a 
motorbike or bike to this bell shaped housing. Its much better to use 
chains and sprockets off a motorbike rather than off a bycycle. The 
sprockets and chains on a motorbike are much thicker, stronger and the 
chain will not come off as easily as it does on a bycycle. You can buy 
these sprockets and chains in a motorbike shop. You might be able to get 
old ones if you ask for them in the motorbike shop/repair shop.
As for 6 times the diameter - you need AT LEAST a gear ratio of 1:6 for 
the small chainsaw engine. Yes - I have found 1:6 to be useful for small 
engines - however this is not set in stone. You will be looking for 
something like 10teeth on the sprocket on the engine, and 60teeth for the 
one on the rear axle.
As for what other parts to get etc. - you could start looking for suitable 
wheels, a suitable brake (callipers brake) off a moped or scooter, a 
steering wheel, suitable wheels etc.

Best of Luck,
-steve

On Sun, 25 Feb 2007, Michael Puhalovich wrote:

> Stephen,
>
>      Thanks for the info.  What do you mean by welding a small sprocket onto the bell housing of the centrifical clutch on the chainsaw engine?  Do you mean to weld a small sprocket onto the fly wheel?  Next weekend threre is a huge neighborhood garage sale.  What parts should I be looking for? I already know that I need a chainsaw; what else should I look for?  Where could I get the sprockets from? An old bike?  And finally, why would the rear axle sprocket be 6 times bigger? Is this just the right number that you have toyed with and found to work?  Thanks again for the help.
>
>                                                                                                   Mike
>  Hi Mike,
>
> A chainsaw engine can easily be gotten to drive a kart. Its just a case of
> welding a small sprocket onto the bell housing of the centrifical clutch
> on the chainsaw engine. Make sure you have the chainsaw engine SECURED to
> the kart, otherwise things could go badly wrong. Also - you have to have a
> LARGE GEAR RATIO. This means that you need a large sprocket (6 times
> larger than the driver sprocket on the chainsaw) on the rear axle.
> Otherwise you will simply burn out the light clutch on the chainsaw
> engine.
> In my opinion, the only way to get it working - is just to try it
> yourself. I dont know if you will be able to get useful advice from the
> mechanical engineers and businesses. I think you should simply go straight
> in and connect up the engine.
>
> The welding kit will be useful for making the chassis of the kart - which
> is normally made from round tubing. However if you dont intend to bend the
> tubes etc. using a pipe bender, you would be better off using square
> tubing as its easier to weld. But - yes, the steel from the Home Depot
> will be fine for a kart. Try and keep the weight down as much as possible,
> otherwise the lawnmower engine will be under a lot of strain.
>
> Best of Luck,
> -steve
>
>
> On Sat, 24 Feb 2007, Michael Puhalovich wrote:
>
>> Hey,
>>
>> My name is Mike and I'm 15. I am strongly interested in building a go cart on my own. The first problem that I have run into is the engine. I have a very tight budget being a kid, and I was wondering if a chainsaw engine would work as an engine. I have heard of people doing it but I am emailing mechanical engineers and businesses first to do research on it and gain common knowledge of the aspects. I have access to a welding kit and other tools as well. Would this be possible for me to build on my own? I have never built one before but I am very good with my hands. Also, I need ideas for building material for the body of the cart. The most common answer has been steel piping that can be bought from Home Depot. Thanks alot!
>>
>