The humble auto-rickshaw. The perfectish adventuring machine.
The engines on our Sri Lankan beasts are an impressively pathetic 10.5bhp. They have tiny wheels, shite ground clearance and bad suspension. They have no real protection from the elements. And they're incredibly unreliable.
All of this pretty much guarantees something will go wrong. Which is where you find out what you're really made of. Hopefully it's stern stuff.
Some of the off-road tracks in Sri Lanka are properly gnarly. Thankfully, with a mere 198cc at your command, this should mean you get utterly stuffed.
Another advantage of that insignificant engine is that it hardly ever needs refuelling. Boom.