I'll urge you to reconsider. Speaking slowly and clearly in a presentation goes a long way in retaining attention and interest from your audience.
I'll quote Paul Graham of Y-Combinator here "Err on the side of speaking slowly. At Rehearsal Day, one of the founders mentioned a rule actors use: if you feel you're speaking too slowly, you're speaking at about the right speed."
Presentations can feel "slow" if they lack passion or enthusiasm - but increasing the speed will do little to help on that front.
If you haven't yet - record a video of yourself delivering your pitch - it will tell you a lot about where things are falling flat.