Fitments
70-99 B.T.(excl. TC); 71-03 XL (NU). With mechanical advanced ignition
Part Description
Breaker weight spring set. Heavy Duty
Stronger than stock. For slower advance curve, used to help solve detonation issues. Also less breaker weight rattle during idling and improves idling stability. Note that stronger springs may require carburetor adjustment (richer). Note: 516300 is standard replacement, 516301 is heavy duty, 516598 is extreme duty. Mixing different spring strengths will give additional fine-tuning options.
