RE: Extreme Flight 87" Yak 54 - Build & Fly
Dick, your lower bolts a up higher and more to the outside of the firewall, I can see why you setup would be stronger. If you look where the lower DA mount holes are, you can see why there is enough leverage to crack the firewall.
Mine firewall is not de-laminated, it's actually cracking straight through imediatly below the tri-stock. I had to wiggle the engine to see it. I'll pull the cowl off tomorrow and take pictures.
john