Hmmm, are Speedmaster and America needles the same?
You may want to try some TBS needles, Triumph part #T12410240. You can easily change these out yourself as well. They have a different taper, allowing more fuel. You will need to adjust your air mixture after the swap, so if you have an 05 or above, make sure you have a "D"tool. More instructions can easily be obtained if you need them.
This all depends on what your current symptoms are. Throttle position is your gauge/guide. Check it out and post your findings.
What year is your bike?
