I'm still running OS160's on all of my glow Pattern planes (yes I'm migrating to electric now). Once you get the pipe + header to work correctly (I had problems breaking headers until I figured out how to mount the pipe) it's a good setup and very reliable. I use a slightly different method to set up the pump and carb. It works for me so you may want to give it a try if you have no one to help you:

1. Break the engine in correctly according to the instructions. It's a ringed engine so this is pretty easy.
2. Install the desired prop and get the pipe close to where it should be based on someone else's experience or recommendation (plenty of this exists already).
3. Don't touch the pump setting yet - just run the engine, tune the needle for max. RPM at wide-open-throttle (W.O.T) and record it.
4. Keep shortening the pipe length until RPM no longer increases.
5. Add 1/2" ~ 3/4" to the pipe length that you found to be optimum.
6. Run the engine, tune for Max RPM at W.O.T. and open the needle about 2 - 3 clicks - use the pinch test to fine tune the needle.
7. Stop the engine and see how far the needle is open. It should be about 1.25 ~ 1.5 turns.
8. Adjust the pump pressure until the engine runs happily at 1.25 ` 1.5 turns open at WOT.
9. Don't touch the pump setting anymore.
10. Adjust idle to about 1700 ~ 1800. Play with the tlrottle and low-speed needle until this happens.
11. Check transition from low - high. Adjust low-speed needle accordingly.
12. Idle mixture should be just slightly rich. You'll know it's right when it transitions smoothly form low to high AND it comes back down to idle quickly. If it takes a long time to "slow down" - it's still too lean.

You need to set things a little rich on the ground because in the air the prop will unload - even at idle. In order to get good downhill braking the idle mixture cannot be too lean.

As far as pipe setups go - Cut the header as short as possible: leave about 1" of straight tube on on it. Use a short piece of aluminum pipe coupled between the header and pipe with short pieces of pipe coupler to adjust the pipe length. Fasten the pipe at the front so that it can't move side to side very much. The whole idea is to let the engine move while not imposing any stress on the header. The short piece of pipe between the header and the pipe allows movement and pipe length adjustment.

As I said this all worked for me. YMMV. Oh yeah - use an "F'" plug and 15% nitro. This will haul an 11 lb. airplane all day long unless you're flying Masters or FAI. By then you shouldn't be flying an 11 lb. airplane anymore! LOL

John Pavlick