Have you ever encountered a sled that starts to break exhaust springs, for no apparent reason? Quite often it is due to the exhaust system contacting the frame or chassis; look for compressed bump stoppers that allow the system to sit lower in the chassis, or compressed rubber pads that let the system shift. A change in exactly where the exhaust is positioned can allow contact with the chassis, and when this occurs you can see exhaust springs starting to break. Remove the exhaust system, inspect it and there you will find the point of contact, often with a shock tower, that allows the transmission of vibration and leads to springs breaking.
During the normal course of riding, exhaust springs can break with time and miles. This can be prevented by applying a dab of hi-temp silicone in between the coils to dampen any vibrations. Extra security of the junction can be had by installing a safety wire through the spring, so if it breaks the exhaust joint will continue to be held tight.
Also pay attention to the spring tension; the coils of the spring should just start to come apart in most locations. The spacing between the windings at the center of the spring should have .040â€ to .050â€ clearance between them when properly tensioned (can be measured with a feeler gauge). Too much tension can also lead to premature breaking. Often the metal tabs on the exhaust system (which the spring connects to) can be reformed to adjust the tension, using a tool like a locking pliers.