Whilst not ideal, you'll be OK to ride for a short while without a fuelling device. There is a risk, in the long term, of the bike running lean which can result in trouble. The thing is though, without adding fuel (decreasing the air to fuel ratio) you aren't going to be seeing any of the benefits the air filters/improved induction can bring. Plus, the O2 controller and fuel mod will on their own make your motor much more tractable and nicer to ride as well. You'll be surprised at the difference they make - they're well worth the investment, both in terms of peace of mind and performance.

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