Well some friends at the field gave me the 30 questions when the second motor failed. And this is what I had to say. I have 6 gas motors that all use the same gas. (no problem) I use Red Line syn at a ratio of 32:1, 8 OZ for two gal. I get my gas at a place that sells Ethanol free gas just for my airplanes. I get the 87 octane. I use a 19x10 prop for this twin 40cc which is recommended. I don't firewall it 100% of the time, and I have good air flow. At least it worked for 14 flights the first time. The motor ran great! I just don't understand. The next time I will run with the cowl off and try tweaking the carb a little. For what, I don't know, but I will be using my temp sensor often.
I believe this plane is cursed! The number of and verity of problems exceeds all other planes in the past. My throttle servo failed twice. Two new out of the box Hitec servos. Again my radio failed during the first attempted maiden. The throttle ratchet failed. No servo response displayed on the radio. Sent it in and they said NTF. I made them open it and clean the ratchet. Now it works just fine. My NAV lights failed because I used 6.6V rather than 4.8V on the receiver. Did not know that. And the LG issue is still unresolved, just have to make near perfect landings. But all through it all, my Citabria is still not scratched.
The first photo shows air intake. Notice that the center air scoop is blocked off. this causes ALL the air to enter at the cylinders. The second photo shows one side where the plugs extent past the cowl. This also allows air to exit. The third photo shows the bottom where the exhaust stacks extend past the cowl and also allows air to exit the cowl allowing more air flow. I don't see any problem with this setup, but some will say the more flow, the better. I say, this is enough and it is a scale model, not a high performance aircraft, and I don't want to butcher the cowl up.
Anyone see a problem with my fuel, prop, setup?