K-KH  and XL-XLH through 1964

The circuit breakers on the K-models and the 1957-1964 Sportsters are different. The differences are very slight, but rather important for proper alignment and operation of the circuit breaker. The Spare Parts Catalogs show different parts, but you can't tell exactly what's what from the lousy illustrations.

My KH came with a magneto. So I did what most people do - I bought a bunch of circuit breakers at the swap meets. I figured one of them would have to be the correct one. Today I started examining them closely. After some head scratching, I figured out the differences. Sure enough, one of the three is a K/KH unit. I've documented my mistakes, and hopefully, you'll be able to buy the right thing the first time around.

K & KH	XL & XLH
John Hewson's 1953 K The adjusting screw points toward the front of the bike The cable makes a diagonal line through the stud.	Don Chasteen's 1957 XL The adjusting screw points outward nearly 45° The cable makes a straight line through the stud.
The Housing, Timer Shaft has two variations - the 32511-37 was used on the 1952-1956 K and KH, as well as W and G models, and 74" & 80" side valve twins. Note that 1937-1946 versions, same part number, did not have the cutout in the rim (shown below at 3 o'clock and 5 o'clock) for the adjusting screw. The 32511-57 was used on the 1957 - 1964 XL and XLH. The only difference is the position of the two mounting holes. The housing is about 2-3/4" tall - with the shaft and gear (Shaft and Housing Assembly, 32506-37 or -57), it is about 5" tall. The OHV Big Twins use a somewhat similar housing, but it is several inches taller. The Shaft, Circuit Breaker 32528-37, and Gear, Circuit Breaker 52531-36 was used on all the models listed above. In addition, the gear was used on OHV Big Twins.
K & KH – Housing, Timer Shaft – 32511-37 The wire hole is at 9 o'clock The adjusting cutout is at 3 o'clock	XL & XLH Timer Shaft Housing – 32511-57 The wire hole is at 11 o'clock The adjusting cutout is at 5 o'clock.
The Screw, Timer Adjusting also has two variations - the 32593-47 was used on the 1952-1956 K and KH, as well as W and G models, and 74" & 80" side valve twins. The 32593-57 was used on the 1957 - 1964 XL and XLH. The difference is the position of the hole for the advance control wire - in two different dimensions. The Shaft, Circuit Breaker 32528-37, and Gear, Circuit Breaker 52531-36 was used on all the models listed above. In addition, the gear was used on OHV Big Twins too.
K & KH – Screw, Timer Adjusting – 32593-47 The wire hole is at a 45° angle	XL & XLH – Screw, Timer Adjusting – 32593-57 The wire hole is perpendicular
K & KH Adjusting Stud – 32593-47 The wire hole has a definite slope	XL & XLH Adjusting Stud – 32593-57 The wire hole is almost horizontal Note: 1961-1964 XLH smooth-sided base shown

The 32579-52 [circuit breaker] Base assembly has two different variations, and looks a lot like the Base used on the W, G, and OHV Big Twins. The 32579-49, used on the W, G, and FL incorporated the new-style points and condenser. Those engines had plenty of room for the wire to the coil. The 1952 K model did not, so a .20" recess was cut into the bottom and the part number changed to 32579-52. Otherwise, they are the same.

We believe that in 1961, Harley decided to eliminate the "waist band" and save money by eliminating a machining step. These "smooth-sided" bases appeared on 1961 to 1964 XLHs, but the part number did not change. The reason, we think, is Big Twins from 1961 to 1964 used a dual-point manual-advance circuit breaker. The raw shell of that Base is the same as the XLHs, but they had to change all the holes and things to accommodate two points and two condensors. At this time, they just stop machining the "waist band" into the raw base. None of the dual-point distributors we've seen have a waist band, and we think 1961-1964 XLH also do not have the "waist band". Mysteriously, the recess at the bottom for the coil wire was reduced from .20" to .10".

 

W, G, Big Twin – Base – 32579-49 Recessed "waist band" in side No recess in bottom for wire

K-KH-XL-XLH 1952-1960 – Base – 32579-52 Recessed "waist band" in side .20" Recess in bottom for wire

XLH 1961-1964 – Base – 32579-52 Smooth sides .10" Recess in bottom for wire