I've jus got the RED JEWEL? and have sent the mine kart with the bad guys in off the track into the pit what dod I do where do I put the red Jewel, also how do I move the Arm of the statue, so that I can use the crystal floaty thingy?

Go in the lower right part of the map (where you see three tracks merging). Stop right after the merging point and drive the cart backwards. You will open the door on the right and find yourself into a large room with a pool. Jump onto the floating crates, whip INTO the left waterfall and you will find an object to put into the small pyramid in front of the statue. The block will rise and you'll be able to reach the place where to put the red gem.
To activate the statue's arm, you need the green gem as well (see my post in "King Sol's Mines: Blue Gem" thread).
Good luck!