Sup, guys!

I’m looking for the movie from 70-80s.
Somewere in some mountains, presumably Andes, there is a mining camp. They dig gold or emeralds or something precious, don’t remember exactly.
Then some gang robs them, stealing everything, then the car with all their loot falls into mountain river or waterfall.
Some guys make an expedition to recover these valuables.

They drive to that waterfall with special equipment, pot some ropes and cables over the river using a crossbow, put a diver into the waterfall and recover the crates with that gold/emeralds/etc.

There was a scene when they drive there, on a gas station some guy from the team get into a brawl with a biker. The biker has some kind of flail with a spiked ball, and the guy uses a tin bucket to fight off that flail, finally defeating that biker.