This article is a joint effort by Hippysmack and IXL2Relax with some helpful guidance from the XLFORUM.
See also the List of Parts Catalogs in the chart below.

• In addition to owning a service manual, the next best piece of literature you can own for your bike is a factory parts catalog (AKA factory parts manual ¹⁾ or parts book) for your year model. The parts catalog is designed to list all parts for replacement associated with your year model motorcycle which should not be confused with the parts and accessories catalog ²⁾ which references custom accessory parts, bags, clothing etc.
• Having the service manual and parts catalog by your side while you are working on the bike provides you a ready reference to help answer questions that might arise. ³⁾ Most parts catalogs include some exploded Parts Diagrams which may also help when some unexpected part hits the floor and you want to know where to put it back.
• There are also Online HD dealers who sell parts and provide images of the parts catalog pages for reference with a listing of the part numbers and prices to purchase. Some dealers have the updated part numbers listed, while others may have only the part number available at the time the page images were created.
• There are many uses for the factory parts catalog.

• Deciding why you need a parts catalog will determine which one (as in the catalog part number) and how many catalogs or versions you want or need (if any).

• For General Parts Ordering: Most any edition covering your year model will suffice when ordering from the MoCo since they will have the most current information on what you can order. Giving them the part number from your book, rather than simply a description of the thing under the lever, will cut down on their searching and possible confusion of what you need.
• See also the Ordering Parts section below.

• If You Have a Mid-Year Introduction Bike: You’ll probably want the updated edition for your year model which, most likely, would be the -xxA catalog number. Since a first edition catalog was designed for the start of the season, mid-year changes will probably not be in the first edition catalogs. But, that would depend on the issue date of the catalog as opposed to the new part’s implementation date. All catalogs were not published at the same time each year.
• See also Parts Catalog Editions to help distinguish between the different versions of a parts catalog for your year model.

• For Restoring or Historical Reference: If you’re wanting to know what parts came factory installed on your bike, the first edition parts catalog is probably your best bet. If that is pre-1979 and your bike year model is not in a ‘full catalog’ year and you’re a stickler for the facts, you may want to invest in a supplement catalog in addition to the full catalog that it supplements instead of the -78A (published in 1981) or -78B (published in 1989). The 79-85 parts catalogs are the same also with the -85 (published in 1985) and the -85A (published in 1990). This isn’t necessarily a bad thing as the MoCo tried to keep parts ordering up to date for your ride. It just makes it more challenging, for those trying to restore their bikes to original parts or to verify factory installed parts when the bike was new. Some Technical Service Bulletins give dates, VINs and / or engine numbers for when procedure or part changes occurred. Lastly, the 79-85 parts catalog does not list parts for earlier bikes although parts in that catalog will fit prior years.
• These also may be important to you;
  • Looking for parts that were installed on your year model
  • Parts Catalog Editions
  • Parts Catalog Supplements
  • Cross Referencing Parts
  • Obtaining Part Specific Information
  • List of Parts Catalogs (by catalog part number)
  • Sportsterpedia History Section (changes from Service Bulletins and other sources shown within year models)

• Sounds obvious enough but sometimes, especially with phone in orders, when to explain the part you need, without having part numbers, confusion between the customer and the MoCo parts department can end up with you receiving the wrong part after waiting a week for it to arrive, delaying your project while you re-order. If you could give the correct part number to them, it will sometimes smooth out your transaction.
• The MoCo will often have an updated part number for a parts upgrade that they are now selling instead of the number / part in your catalog. But, with you having the original part number, it will help them zero in on the part you’re needing. Generally, it can be said that upgraded parts work better than the originals as time and experience shows many flaws. But, that is not always helpful when buying elsewhere since some parts were upgraded to match other parts that were upgraded and are not compatible with other original parts. When ordering from the MoCo, they should be able to tell you of any changes needed to use the upgraded parts especially with parts and accessory items. But, in general, the MoCo doesn’t get into modifications of OEM parts.
• Many parts for older bikes are obsolete for parts ordering from HD unless they are universal enough not get too cold on the shelf.
• We also have to deal with Parts Catalog Errors and Inefficiencies

• There are a number of HD dealers online that provide virtual parts catalogs from which to order replacement parts. These online microfiche include images and part numbers to help a customer order the right parts. This online service is actually provided by a third party that creates parts catalogs for many different manufacturers of a variety of products. The online images appear to be taken directly from one of the physical HD parts catalogs and most often are accurate. However, you do not have a choice of what version of the physical catalog is presented as your online virtual catalog.
• When using the online resource, you will be asked for a very specific model and a particular section of the bike you wish to see, such as the Front Forks. The displayed information will be divided into two parts, the illustrated diagram and the part number listing (with descriptions). The image can be enlarged with typical web browser functions (mouse wheel, Control + or -, etc.). If you want to use the illustrations as a reference when working on the bike, you may need to find a way (various browsers make this easier than others) to capture the images so they can be printed on paper to take to the bike.
• These virtual online catalogs are intended to give you the part number you need to order from this particular dealer at this time. If a part number has been obsoleted and the dealer has no stock of the old part number, there will be no price listed. Also. if the virtual catalogs have not been kept up to date, they may list older part numbers than the currently available versions. ⁴⁾ When ordering, you might want to ask the dealer if any of your ordered parts have been superseded by later variations. Or, you may want to ask them for that particular part number instead of a later version if you are attempting to restore your bike to an original configuration.
• In many cases, the parts images provided of a particular section of the bike in the online virtual catalogs cover many models of that year. That means some of the illustrated parts may not be valid for the model you have chosen. In such cases, that part is not listed in the part number portion of the catalog – it is simply ignored. An example may be where illustrating the front wheels & brakes, a model that has only a left-side brake may still use an illustration that shows brakes for both sides. Here, in the parts listings, only the left-side parts would be listed with the right-side parts wholly missing from the part number listings.
• Some of the online resources provide a way to enter a part number to be searched with the response being a listing of models for which that part is specified.
• Some online virtual catalogs do not show part numbers for the obsolete parts (no longer carried by the factory parts system). Some vendors will show the obsolete part but have no price. Sometimes, if a part has been replaced with a new part (& PN), they only show the new PN, meaning you cannot determine the old part number. ⁵⁾
• Since the MoCo has started to implement an entirely new part numbering scheme, without a year-based suffix, part number tracking will become more complicated in the future.

• You can still find NOS (New Old Stock) original parts on the web from time to time and from some of the NOS online stores.
• When buying from online auctions or bulletins etc., it helps to already know the part number you need especially when dealing with vendors that also sell old slippers and antique cigar boxes but just happened to have come across this HD part they’re unfamiliar with. That way at least, you know if the part number they list is suppose to fit your bike (if their number is correct, that is).

• Some of the illustrations in the parts catalogs also double as an ‘assembly order’ to help give you a visual example of how the parts fit together. Sometimes it helps seeing the exploded parts diagrams, ⁶⁾ so the parts catalog is handy to have even if it's just for the exploded views to be used during disassembly & reassembly. ⁷⁾
• The illustrations also show what parts are supposed to be there. This helps to determine if something may have gotten left out when the previous owner had the bike.
• Many of the illustrations do show the correct features of the different parts i.e. a washer with or without a tang, 7 or 9 spokes on cast rims, or the different features of a handlebar. Many of these features are not mentioned in the text of the catalog.
• Some of the online parts stores have the exploded diagrams posted, but they can be very small or you can only see a bit of the diagram at a time. ⁸⁾ If you want to use them for reference, you may need to print off the image as a full page diagram.

• The parts catalog shows the parts for all the different Sportsters for the year(s) that certain book services instead of one model at a time.
• For OEM parts: Long year span parts catalogs (53-63 or 86-90 etc.) or the practice of owning many parts catalogs can help determine which year models shared the same part number. Just keep in mind, the parts listed are the ones that were in circulation at the time the catalog was written, not necessarily the original part number or the current part number. Consequently, part updates / upgrades may be listed instead of what parts came factory installed unless the parts are specific to only certain models and still currently being sold by the MoCo.
• From aftermarket sources: Aftermarket parts most likely will have their own part number for an item and some will also list the corresponding HD part number as well. In the case of several different variants of a part, knowing the HD equivalent can be an important factor in getting the right part.

• A few entries may carry additional information besides the part # and year model(s) fitment. They may include color or size and some even have dimensions.
• The back pages of the catalogs have a listing of all part numbers that are included in that certain catalog and the page where they are listed. This is helpful when trying to find out if a known part number was listed for parts ordering for the duration year of that catalog. An example is when you find an OEM part online that is supposed to fit your bike but there was no mention of it in the parts catalog. It may or may not fit a Sportster. The parts numbers from either the catalogs or the online parts dealers can suffer from mistakes.
• Most parts catalogs include at least some fastener dimensions in the back pages also.

• This is where things get confusing. The MoCo created the parts catalogs, not for the historical penning of the exact parts that came on each year model but, for replacement of the original parts during maintenance after the sale. This means the catalog lists the available part numbers (upgraded or changed) at the time the catalog was printed. As time goes by, original parts are upgraded or changed and the MoCo and/or their vendors will no longer make the original part. So, if they no longer sell it, they will list the new part that fits your bike in their updated parts catalog instead of the original part numbers, so you can order the currently available parts. Not that there is anything wrong with an upgraded part, it simply can be confusing when you are wondering why the part you just took off and are holding in your hand cannot be found in a newer version parts catalog or online source.
• Check the date of issue or copyright date of the parts catalog to (hopefully) have the correct information regarding what was factory installed on a specific bike. The first edition parts catalog for that specific year model should list what was factory installed and available for parts ordering although that’s not set in stone. In reviewing the Technical Service Bulletins, it is obvious that innovation was constant at the factory.
• Even having the first edition catalog doesn’t always help. Some new catalogs in different years came with a sheet of paper with them telling that certain pages show a different part number than it should or enclosed is the correct diagram sheet to replace the one that is currently in the book erroneously. So, the MoCo did acknowledge that there were mistakes from time to time in the parts catalogs which was relayed to the original catalog owners. But, you might not have that information when buying a used catalog. Since the dealerships used the catalogs the most, they were most likely the one to catch most of the mistakes and by then, the catalog was already in circulation. So, the mistake becomes the legend…. and cumbersome. Online catalog diagrams and parts listings may also suffer some limitations from these changes as well, especially on the older model years.
• You can also check the Parts Catalog Chart below to see the different editions and dates of publication before you buy if that is a concern to you.

• Getting the right parts catalog can be difficult depending on availability and application. Until the 1979 season, full parts catalogs were only made periodically instead of each year. Any changes in between the full parts catalog years was handled with a slimmer version called a parts catalog supplement. These are harder to come by than the full catalogs but still show up on the net from time to time.
• In general, the supplement catalogs will list only part changes. It is stated on the front cover to which full catalog the supplement will update. Supplement catalogs should be used in conjunction with the full catalog (that it is supplementing) to get use of a full catalog for those year models. So, theoretically, if parts are not listed in the supplement, they would be listed and current for purchase from the previous full catalog as directed from the supplement.
• Example, a full catalog was published for the 1971 season. But, only supplements were issued for the 72-75 seasons. Since the 1971 full catalog will not show parts changes for 1974, you would need the 74-supplement for that. However, while looking thru the 74-supplement and the part you’re looking for is not there, you would revert to the 71-full catalog for those parts not listed in the 74-supplement.
• A 76-supplement was issued in October of 1975 and a 76-full catalog was issued in May of 1976. Theoretically, you would not need the 76-supplement if you had the 76-full catalog. But, since those two catalogs were written seven months apart, there may be changes between the two which may or may not be important to the application. It all depends on what you want the parts catalogs to do for you.

• The catalog part number for all Sportsters (excluding racing editions) is 99451-xx. The last two digits of the catalog’s part number reveal the ending year for which it services i.e. -57 for 1957 or -00 for 2000 without any added letters on the end. For long year span catalogs, it would end in -85 for a 79-85 catalog. These are referred to as first edition catalogs.
• Parts catalog new editions / updates will have the same part number but with an added letter on the end i.e. 99451-xxA and the next edition for that specific service year would be a ‘B’ and the next would then be a ‘C’ instead (if applicable). Some new catalog editions are published towards the middle or end of that seasonal year while other new editions are published years later. So, the newer editions will reflect part numbers that are in ‘current’ circulation, when that edition was published, rather than what part number was listed in the original catalog release or came on the bike.
• The 2nd or even 3rd generation parts catalog (if applicable) will show some different and possibly more information than the original catalog does or there wouldn’t be a need for the MoCo to print it. These changes may include upgraded parts as well as new mid-year intro bike information that wasn’t available at the time of printing the original catalog.

• Without getting into specific errors in all the parts catalogs (which would make a pretty thick paperback) there are many gremlins contributing to the body of the parts catalogs thru the years. It can be frustrating while referencing a parts catalog for your year model to find that a certain part number was omitted completely from the listing with no other part number to replace it. But, it was still available for order. Or, a part number revision / update was not included. Your experience with the parts catalog may depend on experience, necessity and / or expectations. However, a parts catalog published by the MoCo should be considered more accurate than non-OEM parts listings in general since they are the ones that built or had the parts built for our bikes and their critics were the dealerships that ordered their parts. Common sense is that aftermarket suppliers would have to get their information from the MoCo to publish / produce it. So, that would make Harley Davidson the source of their information which would have had to come from these sometimes-erroneous parts catalogs. They are not infallible, but neither are our bikes.
• Some of the illustrations can be even more frustrating. Some show one version of a part with one footnote that leads to several versions but fails to illustrate the changes of the part. Sometimes a piece or a fastener is written in the listing but doesn’t show up at all in the adjacent illustration for assembly location. That part may or may not show up in a different illustration in the same catalog. There were a few occasions where the MoCo sent a letter along with a new parts catalog along with an addendum illustration page due to the wrong illustration being published in the beginning. This would probably have been rectified with the next edition of that catalog if an edition had been published.
• Even with the inherent issue of errors, problems using a parts catalog could possibly be due to you not having the correct version. The year model may be correct, but the book’s part number may or may not be the version you need. See also Parts Catalog Editions.