RE: OS .25FP??
This setup will get you over 16,000 rpm. It is a great mod. The venturi size in the stock carb is really small. You can even drill out the stock barrel if careful. Another mod is to set the back nut on the high speed needle to move the spray bar back out of the venturi. May get you up to 17,000. Fun engine to play with. Lots of potential. I think there were some posts on the RCCA website describing all these mods. A mouse can muffler might even help you more. Not sure at what point they redline though. All engines seem to have a point where they let go. The FP was not designed to rev up super high.
What is this application for?