Panuno, your 40bhp 2 stroke will muller that 47bhp 4 stroke. Good effort for taking a 2 stroke that far though. :-)
That Enfield will sound like a choked up 125 with no throttle response, letting it breathe properly will be the best mod you can do to the bike. It won't do anything except make it safer to ride, you'll have better throttle response and you'll be able to overtake a lot safer/quicker/better. Unless you like being hung out on the other side of the road, because the bike hasn't got the power to pull a greasy stick out of a dog's arse.