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Generator

The Model 125 / Model 165 generator has a long and convoluted history.

The original 1948-1949 generator had a problem - it produced very little current at extremely low speeds. If your battery was dead, push-starting would not work - the generator did not produce enough current to fire the spark plug. This caused a lot of unhappy customers - and unhappy dealers.

Old-timers might remember the good old days when you couldn't afford a new battery, you just parked your car at the top of a hill. Generator-equipped cars, trucks, motorcycles, even farm tractors, with a dead battery can be started by pushing or coasting down a hill and releasing the clutch. This also worked on many 1960's cars with automatic transmissions, but later transmissions lacked a rear fluid pump. Alternator-equipped cars can not be push-started with a dead battery - the alternator requires some juice from the battery to work.

Harley completely re-worked the generator, and released it with the 1950 Model 125. The original generator had two brushes and six field coils. The 1950 generator had four brushes, but the six field coils are arranged differently. If you look closely at the pictures below, you'll see that the North and South field coils are arranged NNNSSS on the 1948-1949 unit, and NSNSNS on the 1950 unit.

Almost all the parts in the 1950 generator are new - the field coils, pole shoes, armature, brush holders, brushes - just about everything except the points and some small parts now carry the -50 part number suffix. The complete generator changed from 30000-47 to 30000-50. The "frame complete" changed from 30100-47 to 30100-47A. The "frame with coils and pole shoes only" changed from 30101-47 to 30101-50.

The new generator proved to be a success, and Harley began an extensive recall - of generators on customer bikes, unsold bikes on the showroom floor, and dealer stock of spare parts. Shop Dope #296, 296 sheet 2, and 304 (See the Shop Dope chapter) describe the recall. Shope Dope 317 gives a wiring diagram for the new generator. The Shop Dopes tell us that customers can now push start their bikes. But what strikes us as amazing is that they say that you can mix and match the old and new parts, and the thing will actually work! We're in awe of the electrical engineers who figured out how to do that.

Somewhere around 1952, there were some minor changes involving the points. See the table below. It appears that this configuration remained through the end of Model 165 production in 1959.

The story doesn't end here though. Sometime in the 1960's, for dealer spare parts stock, the points changed again. See the table below

The story might not have begun where we started. The 1948-1949 field coils and "generator frame with field coils and pole shoes only" have a -48 part number suffix instead of -47. The 1951 Spare Parts Catalog (but strangely not the 1949), shows 30404-47 "Brush spring" - "replaced by 30404-48". These give rise to speculation that there have have been some very early changes - either pre-production or very early in 1948 production. We may never know.

1948-1949
1950-1952?
1952?-1959 Minor changes around 1952.
  • The "set of contact points" 30605-48 contained different parts. The 1948-1949 set contained 30606-47 and 30609-47, while the 1950 set contained 32661-47 and 32660-47.
  • The earlier points used "locking screw" 30509-47, while the later set used "adjusting eccentic screw" 30507-47 and "locking screw" 32669-47.
  • Now the complete generator is 30000-47A, "frame complete" is 30100-47B. The "frame with coils and shoes" stayed the same at 30101-50.
  • It appears that this configuration remained through the end of production in 1959.
1960's Spare Parts stock
  • Sometime in the 1960's, the points changed again. The "set of contact points" is now 30605-48A, the "eccentric screw" is 30507-47A.
  • The part numbers for the "main frame assembly" remains at 30100-47B, and the "generator complete" remains at 30000-47A.

  Last updated: May 11, 2011 ←  Up  →