Well I have my engines run on GAS/GLOW fuel without the flywheel and I don't feel any vibrations differences as to the use of the flywheel, mine run smooth ecxept at low idle where you can feel a very small vibration which I dampen with the use of vibration isolators on my engine mount. this vibration is normal even with the flywheel installed,so to me there is no difference with or without the flywheel.