Thanks. I'm considering a JL F-16. Sounds like my Wren 54 might be a better choice than my Falcon. The Wren engine weighs about 2 lbs. and the Falcon about 3 lbs. Depending on what you have to do to balance it a pound one way or another shouldn't break it.

By the way what is the tailpipe diameter, at the inlet and at the exit?

Thanks,
Joe