Just FYI for your viewers who are contemplating removing their secondary throttle plates, (STP): if you have already gone big bore, by all means yank that thing and enjoy, but: if your bike is still a 250, the STP is NOT the evil, power sucking contraption some would like you to believe. In fact at stock displacement, you probably want it there.

The STP increases the intake tract velocity while the engine is in a low rpm condition allowing more, not less, air/fuel mixture to arrive in your cylinder before the intake valve closes and the computer moves it out of the way once the RPMs start to come up to balance **** out.

On a big bore, the physical volume of the cylinder is obviously larger causing a greater condition of vacuum while the valve is open so anything in the way will eat a little bit of initial umpf, but at stock size, unless you're adding a turbo, velocity is more important than lack of restriction just off idle.

If you are seriously mechanically inclined, and I'm talking to you machinists and fabricators, (not engineers, &#128513 you can give the leading edge of the STP that moves in towards the engine and the trailing edge that moves out a slight break and polish to ever-so-slightly increase the intended effect, but honestly, you have a fun little putt-putt, not a arm socket dislocator so it's probably not worth the effort.

Experiment if you like, but that's the reason for the STP and the clean air ***** didn't do it this time.