Jett 50
Dee,
The Jett FIRE 50 and Sport Jett 50 are one of the most popular, if not THE most popular engines used on the Dust when speed is the objective.
The Dust can be flown with a variety of engines, a 25 will do the job just fine if you are looking for a docile sport plane.
If you have never flown anything very fast before you can start out with a 25 or 32 on your Dust. If you think you are ready for some speed start with a 46FX and a 9X8 prop. If you are ready for a hot machine a Jett 50 with an APC 9X8, 9X9 or 9X10 sport prop (C2 hub) is a good choice.
Spend a little time going through the history on this forum, I would recommend starting right from the beginning. You will find lots of info on various engines. MVVS, Webra and converted DF engines are used with success on the Dust
I own two Jett FIRE 50's and am very pleased with them. Both ran perfectly from the beginning and needed no adjustments to the low speed idle needle.
Jetts are not cheap but are worth every penny.