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Choose from the vehicle applications currently listed in our catalog. Engine sizes refer to the standard engine.

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Breaker weight spring set. Extreme Duty

Product code: 516598
Sale price£17.79

Availability: Out of stock
Estimated supplier restock: 15 November 2026 Supplier estimate, subject to change. Delivery time is additional once stock arrives.

The details that matter

Details

Description

Stronger springs than stock. For a slower advance curve, used to help solve detonation (pinging) issues with compression engines or poor fuel. Less breaker weight rattle during idling and improves idling stability. Note that stronger springs may require carburetor adjustment (richer).
OEM replacement reference 32605-70 (which has standard strength springs).

Note: 516300 is standard replacement, 516301 is heavy duty, 516598 is extreme duty. Mixing different spring strengths will give additional fine-tuning options.

Specifications

Unit PR

Fitment

70-99 Big Twin (Excl. TC); 71-03 XL Sportster (NU). With mechanical advanced ignition

Part numbers

Supplier SKU 516598
Manufacturer part

Specifications

BrandMCS
CategoryAdvance units and parts

Fitment

Part numbers

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