mustangflyboy:

It's a big no-no to use a soft mount or isolation mounts with any gas engine. They will shake the plane to oblivion, make your muffler go bye-bye and vibrate things that shouldn't be vibrated. Your best bet is to use standoffs with most gas engines, unless you chose a BME50, in which case you can use the stock motor mount that comes with the plane. I suspect (after seeing some Patty videos) that it's just a case of too many bounced landings. I've found that the best way to land the Patty is to grease it in and let her roll. Don't slow it down to the point it loses flying speed and just drops. Haven't had any issues with mine not holding up well.