RE: Inverted OS .46 Floods
Inverted 2 strokes are notorious for the issues that you are experiencing. Hemos are good for in-between flights and storage as they will stop the siphoning but at some point you need to regulate fuel flow when you are ready to start the engine. You don't need to move the tank if you use a regulator or pump like the Cline (highly recommended), Iron Bay also makes one. These regulators are to give you a reliable idle and transition in any attitude (inverted, knife edge, ect.) and for that reason are quite popular with Slabs/Profile airplanes. As you are aware it is very difficult to keep a 2 stroke glow plug red hot with the inverted mount because all of the excess fuel gravity flows into the plug and then you have a wet plug. Wet plugs don't work and you waste a lot of time "changing" the wet one for a dry one. You can try plugs with idle bars and other crap stuck on them but that is treating the symptom and not the cause. If your stuck on the inverted mount for scale reasons you can install an on board glow driver that will "light" at a low setting and keep the plug hot. Nelson use to have a great one. The simplest and most cost effective is to simply mount the engine horizontally and that will solve most of your issues, you might still need the regulator if your tank is too far away or too high or low. You might also consider starting your engine with the airplane inverted on a stand and then once running turn it over...easily done with a 40 size airplane. Good luck.