Are you placing the dynomite on top of the wall? Also make sure your candle is far enough away from the flame that the wick has to be long, this will allow for extra time before the candle is lit, the boiler to heat, and the TNT to detonate. Make sure the TNT is directly under the bball so it gets the ball over the hump. There is a web site where you can see the solution if you are really stuck
I had to use it on a different level since the game doesn't give you any help at all.
hope this helps.
http://www.marshu.com/articles/crazy-machines-level-solution-screenshots.php#crazymachineslevels2130