Stay off the grass, especially if you are small. The rocks which hit you can spin you out, or if they don't, they can at least push you into a corner, and then you'll have to reverse to get out.
On the jump over the river, aim your kart slightly left, but don't push it too far or you'll end up in the water.
Instead of following the path through the cave, slide up the hill. This saves more time then you'd think.
(From Mistern64@aol.com) Save bananas and fake item boxes either for the ramp leading up to the jump, or for the bridge. A well-placed fake item box on the bridge is very difficult to get around, as is a string of bananas right before the dash zone.
Confirmed Tricks: How to Jump, Slide, and Skid Your Way to Victory
On the first straightaway, before you get to the winding path that takes you to the jump, turn right (before you get to wooden poles which mark the jump). When you get to the fence, powerslide, and you should pass right through the fence and onto the road leading to the jump. Your time savings are very little, though.
Variant: It is also possible to pass through the black texture without falling into the lake. If you approach the left wall at exactly the right angle ( so that you are just skimming the edge of the wall), you may pass through the black texture, but still end up back inside the cave. Doing this on your first attempt can get you an amazing lap time.
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(Note: this trick is made easier by using a star on the approach.) At the end of the straightaway after you jump across the water, there is a very thin ridge of land to your left that is traversable. If, instead of turning right after the straightaway, you turn slightly left and squeeze in between the jungle texture and the water, you can drive along the ridge until you get back to the main road.
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Variant: Instead of rejoining the road after completing the above trick, you can continue along the riverbank and past the next jungle texture that you come to. You will then re-emerge on the large, green hill which precedes the bridge over the waterfall. After going along the shore, you can either drive down the hill and onto the bridge, or you can jump off the hill and land on the bridge, saving a few seconds.
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Unconfirmed Tricks:Ie. Rumours Floating About on the Web
I haven't heard of any for this track. If you have, please email me.