Help with MMM pinion/spur gear mesh

[Urgeoner]

I just bolted my MMM2200kv on my Revo conversion.
I am in the process of making the pinion and spur gears mesh properly, since there is about a 1/4" gap between them both. I currently have a Jato 54t spur and the stock 18t pinion that came with the MMM. I am thinking about getting a 25t pinion, and hoping that it will be large enough to reach the spur gear. Is a 25t pinion much larger than an 18t? Do you think that it will be enough to reach the spur gear, or do you think that I'll also need a bigger spur gear? My LHS doesn't have anything over 17t at the moment so I can't just go there to find out. It seems that I'll have to order them, and I want it right the first time so that I won't have to keep reordering and waiting.