® The challenging Honda CBX

Honda's CBX1000 is more fun to ride than it has any right to be, and most of the reason is its engine. The bike is also a bit more demanding maintenance-wise that it ought to be, and again, the reason is its engine.
One of my Gold Wing carburetor customers called a few months ago. I was honored to get his call asking for advice on a new bike purchase. New to him, I mean. It was a Honda CBX he was thinking about. Now, this is a guy who clearly had both mechanical and financial limits, judging from past dealings. So what did I tell him? Stay far away from the CBX!

You think you Gold Wing or SOHC guys have it difficult? I mean, you think the vintage Honda four is demanding to own and maintain? Well, let me tell you. Consider the Honda CBX1000. Those of us smitten with it love the thing. But man is this ol' gal quirky and, like the proverbial femme fetale, high-maintenance!

First off is the bike's heat. This accounts for half of the problems of its ownership. Did you know the carburetors' float bowls evaporate to just half their quantity in a couple hours' time? Yup. They do. *That's* engine heat. And they're completely empty -- bone dry -- in just one to two days -- all 300 milliliters!-- adding to the bike's poor fuel economy and making each starting of the parked engine a thing only members of the fraternity do confidently. Didn't know that, did you? The CBX engine's 375 degree F. head temp and nearly 300 degree oil temp just ravage this bike. From dramatic loss of engine power when warm, to piston rings softening in stop-and-go traffic, to the trashing of all the bike's rubber parts, including its cam chain tensioners, oil seals and even its manifolds. To this add unusually high heat-induced crankcase oil foaming, and every single one of these bikes at any given time has some heat-damaged parts and is two to four quarts low on oil.

And complex? While nothing like a modern bike that takes close to an hour to get enough bodywork off just to inspect the air filter and has to be drained of coolant and the cams removed to do a maintenance service-- and don't forget to roll the $4000 laptop beside it so the throttle bodies can be synced-- the cbx is its own brand of complex and surprisingly so for its era. Four cams, 24 valves, six carburetors, two cam chains, valves requiring special tools to adjust, carbs even more so, and not many bikes in the 70s took the almost six quartsof oil the cbx does. Nor has any streetbike since the pushrod Triumph Bonneville needed an out-and-out racing engine building type degree wheel to set its ignition timing. That's not just any degree wheel but one exactly like the Triumph's having cutouts for accessing the ignition with a screwdriver. Gold Wing owners do best-practice cam belt tensioning by rotating the engine until the belt you're doing on its untensioned run is its loosest, then deploy the spring-loaded skateboard wheel. Nothing like that on the CBX. The same job on the big six takes two special tools and more than a little highly specialized technique involving valve cover removal and pushing and pulling and feeling and scrutinizing. Artful, this. Not at all intuitive and not officially documented. And syncing those six carburetors? Very few have the patience, with the result that very very few CBXs out there are running their best.

And with two dozen valves the CBX is *the* poster boy for Honda's 1970s cylinder compression debacle. Like all Hondas designed in the 70s the CBX's valves are extremely short-lived, resulting in all of these bikes having, at the most, only 80 percent of their as-manufactured cylinder compression (and usually less) and thus performing far below their potential. Until rebuilt that is, with a properly performed valve job coming in at a cool $3000, not including reassembly of the engine, and not including the two cam chain tensioners often destroyed by the engine's heat and which fetch a princely $1000-$1700 apiece at current rates, not to mention the cam chain that is worn out by 30,000 miles. And yes, there are two of the chains and the tensioners, plus two more similarly rubber-coated complementary chain guides that also deteriorate from engine heat.

Talk about expensive! Even regular maintenance is painful. A valve cover gasket and the related bolt seals will set you back more than $150, intake rubbers (manifolds) about $300, expert carburetor rebuilding as much as $1500 not including install and adjust. And withe aforementioned evap issue and since this extremely hot-running engine uses its fuel as part of its cooling, you'll be happy to get an average best of 35 mpg, while many owners see less. Worst of all, while the typical CBX needs a lot of attention due to mere designed-in self-destruction, even more involved rehabilitation is needed than usual on most CBXs simply because this bike draws people to it who should not -- should NOT -- own tools. Seriously. Hammer-heads, individuals patently and completely incompetent mechanically, who as we speak are fast contributing to the attrition rate of this iconic vehicle. No joke. So maintenance is above-average costly; spark plugs are the only cheap maintenance item on a cbx!

And engine work...you really don't want to know. But I'll tell you anyway! A top end on a CBX costs $15,000. Remember the head work and the as-gold cam chain tensioners? How about a single gasket that demands more than $250? A good used clutch basket is more than $1200. If needed the high-wear alternator drive coupling, if you can find one, $600. And as with most 40+ year old bikes, NOS factory control cables are long gone and for the CBX precious enough to demand $150 or more when you can find them. Each. And the aftermarket replacements are dismally-poor quality, unsurprisingly.

Truly, the CBX1000 has moved into the neighborhood of, if not 70s Lamborghinis and Ferraris, then perhaps suddenly-very-sought-after vintage Alfa Romeos. It is almost all that those vehicles are: beautiful, brawny, unusual, quirky in design, painfully costly to repair, moderately expensive to maintain, and rather overtly subject to their inherent issues plus even more foisted upon it. Yet for many of us, to whom the machine has permanently endeared itself, the CBX is truly special, eminently appealing -- viscerally so, and a thing woven into our motoring psyche. Granted, it can be challenging to own. But as with any 40+ year old bike, most of that pain occurs at the purchase point of an inevitably much-neglected machine. Because if you can bear the freight, once all the maintenance demons are exorcized, and you accept the bike's need for frequent maintenance, the bike can be relatively troublefree for many years. And very few bikes combine the visual, aural, and seductive physical allure of the undeniably unique Honda CBX.

Further reading:
The sixteen things every CBX owner should know
CBX quirks
CBX myths

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