McFarlane has two softer springs for the Rotax 912; somewhat softer (#6534) and a much softer (can't find the part #). I have been using the 6534 for 26 hours now with no problems. It still has enough tension to keep all the slop out of the system, but does not require such high friction to keep it from creeping forward. It will still definitely go to full throttle if the cable breaks.

Jim