I do believe that a managers motivation can directly feed into the project teams motivation. If the leader of the project is not passionate or motivated about a project it is tough to believe the team would be. Simple compliments and recognition can go a long way in a project team. Not saying compliment every single little thing but complementing them on the tasks you know are a bit more strenuous or cumbersome to complete. I know on my team, our project manager treats out to lunch every now and then after a big milestone has been completed and ensures proper recognition is communicated out to the higher executives when asked. Also a project manager is more involved it helps with the motivation factor of the team overall. It builds a personal connection that can go a long way to ensuring your project team is willing to go the extra mile.