"It would be so nice if something made sense for a change."
Lewis Carroll, Alice in Wonderland
It's no secret that career dealer techs (yes, I know, an oxymoron these days, but...) take a very dim view of aftermarket repair parts. Very dim in fact. Back in the 1970s, in the days when the market was awash with fairing kits and engine guards and saddlebags, and custom seats and tanks, we used to say in the dealership that you always had to add time to a routine maintenance service so you could remove some of this crap before you could actually get to the motorcycle to service it. Why couldn't the designers of this stuff think ahead even that little bit? Califia saddlebags had to have holes drilled in their mounts or you couldn't replace rear brake pads. Vetter fairings had to have extra ground wires added to prevent floating grounds. Virtually everything was mounted with worm drive hose clamps, u-shaped automotive muffler clamps or plastic cable ("zip") ties. Aftermarket exhausts required two people to install, one to bend/wrestle the pipes into alignment with the engine's exhaust ports and the other to tighten the fasteners. Luggage racks interfered with seats and shocks. No two aftermarket shock aborbers in a set were exactly the same length. Aftermarket fork seals quit working almost as soon as they were installed. Non-original gasket kits sealed and held up abysmally, and by the way still do. Ninety percent of aftermarket chassis parts were incompatible with the stock parts. Really, "aftermarket" became a dirty word. Same thing with "accessory." Career techs used to say about the myriad of fairings available in those days, "Universal fit! Right! It'll fit the universe, it just won't fit this motorcycle!"
So a jaundiced eye was the norm. And even today you can tell a career motorcycle tech by what he thinks of aftermarket parts. Naturally, some of this has gone away. Bikes sell very much less successfully now than the heyday of the 70s, the aftermarket has shrunk as a consequence, and today's fully enclosed bikes don't lend themselves well to a lot of add-ons. However, there are still a lot of aftermarket parts, and issues with these products continue. What has changed the most in recent years, is the OEMs themselves are now adding to the problem. You see, OEMs such as Honda are selling reproduction, or pattern-made parts, in an effort to meet the demands of the vintage restoration market. Pattern made exhaust systems, that is, ones not made by the original manufacturer but by a third party, and more or less copies of the original. Not bad parts. Honda is to be commended for this, at least for the effort. After all, few OEMs care at all about their products that are 30 to 40 years old and more. But it has to be said: sadly, some of this stuff is junk! Ignition points, for example. Yes, contact points, but not made by the original major Japanese makers TEC and ND but by Diachi, a Chinese company that makes an absolutely atrociously bad product. Incredibly awful! And sold as a Honda part, in a Honda bag, with a Honda part number. Then there is the famous Honda moly grease, which was mandated for use on their shaft driven motorcycles in connection with a GWRRA-inspired 1982 GL1100 driven flange warranty extension, a great product originally containing some 45 percent actual moly metal content, later revised to 60 percent and depended on by many. Recently though Honda quietly and inexplicably superceded the part number for this grease to a China-sourced run of the mill assembly lube containing a third of the original's moly. Now all those Honda (and surprisingly, BMW) drive shaft bike riders have to find their high content moly grease elsewhere.
But wait, it gets worse. One of the worst failures in Honda's half-hearted attempt to address vintage is the situation involving engine valves. During the original superbike era of the 70s and 80s Honda did something rather unusual for them: they made a series of bikes that shared a basic engine configuration. This was the early DOHC fours and the CBX1000 six cylinder. So many parts are or look to be identical it had to have been intentional. Only one problem. In many cases what looks to be an identical part is found on closer inspection to not be. It's just oh-so-close! The DOHC 750 and the CBX1000 both have 25mm intake valves and 22mm exhausts. Many aftermarket valve sources in fact list the same valves for both engines. But they are not the same. Their lengths differ, and more importantly, their stem diameters differ. These differences were in fact codified by the two engines' valves originally having different part numbers, 425 center code for the 750, and 422 on the CBX1000. Then Honda, no doubt as part of their vintage parts effort, suddenly superceded the 750 valves' part numbers back the CBX1000 part number! But wait! Their stems are different diameters! And not insignificantly, their lengths also vary, enough to be a concern on a shim type engine that cannot tolerate much give and take in valve length. Honda is not to be commended for this. Not good.
But back to the aftermarket, because the real champions of playing fast and loose with reality are the non-OEM parts suppliers. Think about it. These small companies do not have the resources to design and manufacture that the OEMs have. Take carburetor rebuild kits for example. Honda (actually Keihin) made each of their carburetors have a slightly different slide needle. The aftermarket companies can't work to that standard. They don't have the resources. Instead of scores of different needles spanning a dozen models and years of carburetors, they rely on a mere handful. The result is, there may be one carb among the 10 or 20 models on which a particular needle is correctly specd, but it certainly can't be correctly specd for all of the ones it is sold to fit. It's just not possible. The supplier is doing the best they can, but they really can't do it. And it shows. Not to mention the fact that Honda slide needles from approximately 1978 onward are made of beryllium and never wear out. So why would you throw them away in favor of badly engineered crap, and soft brass crap too?!
Valves and valve springs are the same deal. You buy some aftermarket valves marketed for a Honda and you find their stems are significantly smaller than stock specification and fit the engine's guides like a pencil in a Coke bottle. What the....! Do I want to buy valves that will install at or beyond the factory's wear service limit? In an engine being rebuilt? The retailer of this junk blames the engine builder and goes on a tirade against stupid customers. (!) These valves are obviously Chinese and/or made for a different engine and given the aforementioned "close enough for other applications too" tag. This is criminal. Then the valve springs sold by another vendor for the same bike and made, it is said, by probably the best known name in performance valve springs. Just as bad. The package lists more than one brand and model of bike besides yours, and they're fully a quarter inch shorter than stock! What are these suppliers thinking? I'm supposed to put quarter inch spacers underneath each valve?
Now most readers of this article aren't going to appreciate how badly this reflects on the aftermarket parts industry. The aftermarket is in many ways indispensible and both OEM and the aftermarket exist to make the powersports industry great. No argument there. But you have to understand, they are two different worlds. Going back and forth between them is like entering a time warp. All the rules change. You're left scrabbling for something solid to hold on to, like reality for instance! Disorientating, to say the least. The aftermarket world is indeed a place where things get "curiouser and curiouser", where "uncommon nonsense" is the norm, and you are unashamedly compelled to "believe as many as six impossible things before breakfast."