| Diagram | Fig. 3 — GEAR CLUSTER AND TIMING COVERS · ref 102 |
| Subsystem | engine bottom |
| Listed in parts books | 1970 |
Auto-advance unit (54416405)
An auto-advance unit for ignition timing, found in the gear cluster and timing cover area of the motor.
This is an auto-advance unit, the mechanism that adjusts ignition timing as engine speed rises. It shows up in the catalog under the timing cover and gear cluster section, which is where you'd expect to find it since that's the area of the motor where the timing side gears and ignition components live.
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The catalog record we have on this one is thin — a single listing tied to the 1970 model year, without much else to go on for exact fitment across the range. If you're trying to match this to a specific engine, bring in your old unit or the numbers off your bike and we'll confirm before you order.
Auto-advance units like this typically work off centrifugal weights and springs to swing the timing forward as revs climb, then let it retard again at idle. Worn or sticking units are a common cause of erratic timing and hard starting, so if yours isn't moving freely it's worth a look regardless of exact part number.
We've never carried this one. Tell us what you're after and we'll go looking — you'll get a price and photos before you commit to anything.
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