67 XLH Belly Numbers

Classic short-frame models

Re: 67 XLH Belly Numbers

Postby hennesse » Sun Dec 23, 2018 12:54 pm

It has been said that some 1967 XLH bikes had belly numbers that begin with a "667" prefix instead of a "767" prefix.

The OSKRG has a TOP SECRET DATABASE that contains about 90 records of K and XL-models. Each record contains owner, serial number, and belly numbers. Some records have frame date codes. Some records have front and rear cylinder date codes. We've been building this database so we can answer questions like Roadbum's. Jerry Raino's and Roadbums XLH serial-belly numbers are now in the database. We need more - read on...

The XL/XLH and XLCH crankcases differed only slightly through 1966. In 1967, the XLH gained electric start, and the XLH crankcases now differed markedly from the XLCH crankcases. It appears that the factory decided to begin a new belly number sequence for the new XLH cases. Belly numbers had the format XYY SSSS(S) where the prefix included X, the model-type indicator, and YY the last two digits of the year. The model-type was "7" for XL Sportsters. Where did the "6" come from?

From 1930 through 1969 Harley used 5 different belly number encodings (Thanks, Bruce Palmer). The only one of interest to us is the one used from late-1950 through 1969:
Code: Select all
1 = E and F - big twin OHV
2 = S and ST - 1948-1952 Model 125 and 1953-1959 Model 165
3 - W and G - 45 ci solo and Servicar
4 - Not used
5 = K and KH
6 = B, BT, BTU, BTF, BTH - 1955-1959 Hummer, 1960-1961 Super 10, 1962 Ranger, 1962-1965 Scat, 1966 Bobcat
7 = XL

Since 1966 was the last of the B models, the "6" was "available" in 1967. Apparently the factory decided to reassign "6" to XLH.

Let's look at what we have in the database

Code: Select all
Serial #       Belly #
66 XLCH 8430   766-4545

67 XLCH 1468   766-6424
67 XLCH 3554   766-7285
67 XLCH 3705   766-7376
67 XLCH 5552   766-8338
67 XLH 7217    667-2490
67 XLH 7218    667-2494
67 XLCH 7641   767-2814

Wow, what a mess - but we can make some sense out of it. We gotta start by looking at 1966 production. 66 XLCH 8430 decodes to a normal serial of "66 XLCH 4430". Theoretically, it would have a belly of somewhere around 766-4430. This bike's actual belly is only 115 away from theoretical - an expected difference. The Legend Begins says that 4825 XLs (combined XLCH and XLH) were produced in 1966. That would make the very last Serial 66 XLxx 10825 (normal 5825) and the theoretical last belly number 766-5825.

Now we look at 1967 production. Let's start with the XLCHs. Many of the XLCHs have 766 belly numbers. It appears that the factory machined and belly-stamped about 2000 extra XLCH cases in 1966 (766 prefix), and that these were put in 1967 bikes at the beginning of 1967. Later in the 1967 model year, they ran out, and started making new cases - with prefix 767.

Meanwhile, the 1967 XLH crankcases have a different belly number sequence - they have 667 prefixes. Apparently, the factory wanted to track them separately, but we don't know why. There are lots of things we don't know. We don't know if the odd 667 prefix was used on all 1967 XLHs. We don't know if 1968 and 1969 XLHs used odd 668 and 669 belly prefixes - we have no records for these in the database. So everything above is JUST A THEORY. As we get more data, we will see if the theory holds, or it's time to formulate a new theory.

Please help us! Send us your serial and belly numbers - especially if you have a 1967-1969 XLH. PM or email to the Site Admin (hennesse) - or post them here on the Forums, and we'll add them to the database.

1) Before 1970, serial numbers were assigned sequentially to all variants in each model-series without regard to the variant (e.g. XLH or XLCH). So 62 XLH 1001 might have been followed by 62 XLCH 1002, 62 XLCH 1003, 62 XLH 1004. This also applies to big twins, 45's, S lightweights, B lightweights and Toppers.

The same applies to belly numbers. For one thing, the difference between a FL and a FLH was in the pistons and cams - the crankcases were the same, so no reason to track them differently. This continued until 1967, when the XLH and XLCH Sportsters crankcases were considerably different. But how hard would it be to tell an electric start XLH crankcase from a kick-start XLCH crankcase? (OK, someone will mention the different 1966 cases).

2) It's really impossible to take a particular serial number and guess what the belly number "should be" - or vice versa. In some years, XLH and XLCH sales were about the same. In other years XLCHs outsold XLHs by a ratio of 2:1. And we have no idea what the production mix was. In one week, they might have made 50 XLCHs, or 25 XLCH and 25 XLH, or 50 XLH. The next week might have been completely different.

Surprisingly, our records show the serial number and belly number corresponding within a few hundred of each other - for the years 1952 through 1966. In a few years they way overbuilt cases, then used them early the next year - but after adjusting for that, the correspondence continues to track well.

3) From 1967 through 1969, the serial-belly correspondence breaks down completely. In 1967, we have two streams of belly numbers merging into one stream of serial numbers. So, except for boundary cases, like the beginning and end of each year, it's senseless to try and correlate the two.

4) In the late-1950 to 1969 belly number coding scheme, the "4" prefix is not used. Why? Were they expecting the "U" motors (last year for them was 1948) to make a comeback? Did Topper motor scooters have belly numbers? What did they start with? Any Topper fans out there?

5) The 1960's odd/even serial number encoding. Many websites incorrectly state that this started in 1962. I think someone got it wrong, and other websites just copied the bad information. Bruce Palmer says 1960. The Harley Hummer Club's member records show all 1960 bikes having only even leading-digit numbers. They also have a few records for 1960 Toppers, and they had only even leading digit numbers. The OSKRG database shows only even leading digit numbers for 1960 XLs.
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