it will make you over rev some.Good note: on a warmer day(above 0C for example) it keeps the rpm decent,on a cold day it will over rev.Usually you run a w-w-w primary spring with that helix.Usually wrap to 70 with a green spring.
On a 7 C day here one Winter(in April) I ran with it on a River with just ice,no studs and my speedo climbed to about 118.5.I did it seven times over and over with same results.