Breaker weight spring set. Heavy Duty - 70-99 B.T.(excl. TC); 71-03 XL (NU). With mechanical advanced ignition 3545 Note: See 508375 for replacement

Note: See 508375 for replacement foam filter element

long-lasting construction

No matter what you choose

NOTE: Not for 1200S models

Inner Primary Mainshaft BearingFits most OEM and most aftermarket inner primaries

Breaker weight spring set. Heavy Duty - 70-99 B.T.(excl. TC); 71-03 XL (NU). With mechanical advanced ignition 3545 Note: See 508375 for replacementStronger 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.