#4686
Scott
Member
  • Topics: 1
  • Replies: 5
@sborder92
Newcastle
GT125R

If you stick with the standard air filter and end can then no. The stock downpipes are sleeved to half the diameter of the outer pipes and the standard can is too, which would maintain back pressure. But if you’re using a different end can, or have changed the intake system in any way you’ll need to up both jets to next size. You might find you need to fit a baffle too if you’re using an aftermarket can as loss of back pressure means you’ll get zero power at full open throttle.