I've never run the hard servo saver spring nor is mine completely locked down. it's a mm or 2 past whats recommended in the manual with blue locktite holding it in place. I also run a Futaba BLS 351 servo. It's been flawless. I did strip the stock plastic horn early on and have been using the Serpent Aluminum horn ever since. Again zero problems. Double and triple check you EPA adjustment and make sure your not over stressing them is my only advice.