I hope I'm stating this correctly, but here it goes. I've heard that when you put in a power up kit, you have to do the whole thing. I've heard you can't just do the main and not the needle. Why is that? Why can't you interchange all the needles, pilots, and mains of they are all correct for that carb. I'm fiddling with a CRF230 carb. Someone said to use the stock needle cuz it's better than the powerup needle. The next guys says you can't!!! What's the reasoning behind this?