I only have 4 gas engines 20cc to 55cc and have left the spring on now for approx. 6 years. Never had a problem with the 3 metal gear servo or the one nylon a gear on the 20cc. I sure someone has had the same luck on removing the spring..............I say this issue is a toss up filp heads..... keep spring......... tails remove spring.............do what makes you feel right