Thank you for the opportunity to help you with your question!
Motivations, are in essence a type of psychology you have to learn or master in business. If people are passionate in what they are doing, chances are, the monetary attachment isn't important to them. To motivate correctly, you have to learn why each person is here to begin with. Are they here for the money? The opportunity? The legacy? Once you figure this out, you have to motivate them properly, by catering to their specific needs.
The human brain, reacts positively with praise and appreciation. Make them feel wanted. Tempt their hard work, with celebratory cheers and encouragement. Tempt them with the thought of finally, completing the project, with the fruits of their labor.
Of course some people, will want the money. And for those people it's simple.
Please let me know if you have any more questions. I am a student from MIT, and i would be happy to answer your questions. I promise 100% on all of your assignments! Take Care!