I am currently breaking in a VM120 B24T. I dont use a fiala at the moment. Is it absolutely necessary to use the fiala? With a XOAR 30x12 wooden prop I find the rpms keep fluctuating on idle and full. I have only started the engine 2-3 times. I am getting very high idle around 1300 and the max rpm is around 3800 on the ground. They start great but I find the transition to be a bit sticky.. Could this be due to the fact that its still not even seen 500ml of fuel? BTW, I have a Fiala 30x12 on order, should take few weeks. I use Valvoline oil as per manual. What could be the reason for the surging rpms? Needles are stock and the engine is brand spanking new.

thanks.