Hi,

No, I haven't yet. It will work fine though. The exhaust gas velocity and temperature, (which are used among other things to determine tuned pipe dimensions) would be different than either a pure glow or a pure gas engine, but easily within pipe length adjustments. Just start long, and shorten in small increments until you get max rpms. Then lengthen it back to the last step before you got max rpms and you're good to go. You probably won't see large gains unless your exhaust timing is about 150 or more, with as much as 170 or so being a good tuned pipe exhaust timing. As always, everything has to work together in an engine, so if your carburetion and port timing isn't working with the pipe, and all targeted at about the same rpms, you won't have a good combination.

Let us know how it works,
Good luck,
AV8TOR