Your engine will run fine without nitro, however it won't idle well. Use a hotter plug than normal and you might be ok. Same principle applies to two strokes. With the extra stroke and no ignition the 4 strokes cool off a lot faster, so they need to be kept warm if less nitro is used. Ideally, in the long run if you plan to do this for a long time get an onboard ignition system. (about 70 bucks)
Max