[Kartbuilding] hp required for karts

Stephen Burke sburke at burkesys.com
Wed Aug 27 00:12:21 IST 2008

Hi Jace,

I used to think that single engines with high HP was the way to go, 
however I have since moved to using small engines off motorbikes which 
have a combined gearbox.

Although it would be possible to get high torque and ungoverned speed from 
the 10hp ride-on lawnmower engine, the top speed would be very low. Also, 
in order to obtain a large gear ratio, a drive chain would have to be used 
(i.e. two sets of chains and sprockets), as it can be difficult to get a 
single large sprocket for the rear axle.

The pit-bike engine with the gearbox would be the best way to go. It might 
take a little more effort driving the kart, in having to change gears, but 
it would be worth it, as you would have the best of both worlds, high 
torque and also high top end speed.

Im glad you found the kartbuilding.net website useful. Its good to get 
positive feedback about it. I hope to keep adding information and 
resources to it whenever I get a chance. If you have any photos or details 
you would like to add, feel free to drop it in an email and I can put it 
up so others will be able to get some use from it.

Best of Luck,

On Sat, 23 Aug 2008, Jace Brand wrote:

> Hi guys,
>  I am thinking of making a kart, I guess a kind of on/off-road kart of
> sorts.  I am aiming for a ground clearance of somewhere around 3-4", which
> should be enough for foot-paths and carparks.  I am curious, however, as
> to the HP that will be required.  One house we will be using the kart at
> has quite a steep driveway, and I was wondering what you would recommend as
> an ideal HP.  I have access to a number of possible alternatives, ranging
> from a 10hp ride-on lawn mower motor (horizontal crank), and also a 125cc
> pit  bike motor and gearbox.  The going concencus among friends is that
> the pit-bike motor is surely the way to go?  I'm not convinced, as the
> 10hp ride-on has no governer, and would be suited bto low RPM torque?
>  The kart, i would hope, could obtain a top speed of around 50-60 kph
> would be ideal!
>  Any help that you guys can give me will be greatly appreciated!
>  Many thanks, Jace!
>  p.s you guys have got, without doubt, the best information site on the
> net, and it is very refreshing to find a site that seems to be geared
> towards simply helping the average builder out without having to find the
> need to charge an arm and a leg to offer advice!  Thanks guys!

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