|
- The number one problem with these machines is the carburetors: their as-manufactured main jets vary widely, and worse, most have been ruined by unprofessional handling (including carburetor rebuild kits).
- Taken together with these carbs' fast-wearing brass needle jets and jet needles, the result is all of these bikes run extremely rich.
- The number two problem is these engines eat their sprag-type starter drives and there are no replacements. Though I've called it number two, I regard this a deal-breaker when planning a restoration. Bikes designed to electric start should not have to be kick-started.
- The number three problem is folks run these bikes out of oil, which trashes the top end, especially the cam followers.
- Because of the engine's eccentric adjusters, cam follower damage results in the valve clearance being made impossible to adjust.
- The collectability of the "Black Bomber" (1965-1967) has inflated the value of all years' parts on the used market.
- These engines build up a significant amount of crankcase sludge in just a few thousand miles and only engine disassembly can remove it.
- The later aluminum clutch pushrod breaks from inadequate maintenance of the clutch and final drive chain.
- This pushrod and its release mechanism are rare parts now.
- The engine's cam chain tension is invariably neglected.
- The engine's oil filter is similarly, famously, overlooked and consequently is typically packed full of detrius.
- The original selenium rectifiers are failing and silicon replacements were not only recommended by the factory, but even in a bike in good shape they increase charge output through increased electrical efficiency.
- As with many 50+ year old motorcycles, the most commonly replaced parts are scarce.
- On the other hand, many of these engines are being sold piecemeal, thus used crankshafts, cams, cylinders, heads, transmissions and even crankcases are plentiful.
- Honda sold a special 0.0012" feeler gauge for use in adjusting the engine's valve clearance.
- No one should use this demonstrably unreasonable clearance specification.
- As with other early Hondas, this engine has soft valves that potentially wear very quickly. However, unlike other Hondas, it also has soft valve seats, which happily results in less valve wear.
- There are good quality cast pistons available.
- Wiseco also has available 1mm and 3mm -over forged pistons. And by special order a 4.5mm-over piston.
- Dozens of aftermarket companies sold gasket kits for these engines, a few reasonable quality, but most not.
- Part of the alternator is switched in and out of service by the headlight switch, thereby supplementing the voltage regulator in its charge control function.
- Kind of a useless (if unique) system, mechanics from the very beginning have permanently wired in the switched half to increase the bike's overall battery charge.
- Later, the headlight-always-on CB500T had this modification from the factory (via a pigtail inside the electrical box).
- The CB450 and CB500T transmission is surprisingly robust and durable--actually massive for a mid-displacement bike.
- There are a lot of very subtle parts differences between the 450 and 500, with the result that many are interchangeable while some are not.
- Probably because owners of these machines don't want to spend money on their upkeep, the grossly inadvisable use of silicone sealer is common on the 450/500 engine.
- An interesting characteristic of Hondas this old is their replacement left side engine covers are scarce (and priced as if made of gold) apparently due to almost universal tipover damage.
- Factory control cables are long gone, leaving owners only the comparatively poor quality aftermarket option.
- Similar to the CB175 and CB350 twins, the oil drain plug on the CB450 and CB500T is an unfortunate design that seizes to the crankcase and is often impossible to remove using the usual tools.
- Because the centrifugal oil filter canister is pressurized before sending its oil upward in the engine through the clutch cover, its thin o-ring plays a surprisingly critical role in maintaining proper engine oil pressure.
- The oil filter access plate in the clutch cover contains a transfer valve that if damaged or absent (after a clutch cover collision-related replacement) can malfunction and destroy the engine's camshafts.
- Though once popular among some, the valve clearances cannot properly be adjusted with the engine running.
- Honda has historically used copper-plated steel head fastener washers on its engines, but the 450 and 500 have solid (not plated) copper washers beneath the two right-side head nuts.
- These washers are found at these spots because this engine oils its top end from the right side.
- Some like it and some don't, but the CB500T revised the tuning of the 450 to give it more streetable low-rpm power.
- Do your bike a favor and switch this machine that will sit more than it is ridden to silicone brake fluid.
- Sintered all-metal disc brake pads will improve braking.
- Honda's funky gas cap latch recall affected these bikes as well.
- The CB500T's carburetors have added to them air cutoff valves that reduce afterburn, as well as vacuum ports to aid synchronization, but are otherwise identical to those on the CB450--they even have exactly the same jetting--making them useful updates to the 450.
- The cylinder head casting on this engine has to be one of the most unique, most interesting, least Honda-like of anything Honda ever mass-produced--it's more 70s Italian than 70s Japanese.
- The roughly 100-watt alternator on these bikes doesn't have the capacity to support heated clothing.
- Racer Todd Henning's 450 ran two spark plugs per cylinder.
- There is a much better way to time the cams than by levering them with a screwdriver.
- ?
- ?
|
®