® CB500/550 glitches, quirks, peculiarities, observations, nuances and helpful tips


The CB500/550 is my favorite vintage Honda. Yet, there are many not-very-well-known characteristics, gotchas and solutions owners would do well to consider. Here are just a few of them. I'll include a few CB350F and CB650 items also.


  1. The CB500's aluminum clutch pushrod does not hold up to the abuse of an improperly maintained throwout mechanism
  2. The pushrod is aluminum for a good reason
  3. The CB350F, late CB550 and the CB650 are the only SOHC fours with a fast-idle system
  4. The stock exhaust can rust out pretty quickly, but this can be prevented
  5. The CB350F, 400F and CB500/550 has a drive chain that is non-o-ring type requiring more frequent lubing
  6. Annoyingly, the CB500/550 throttle has one of the longest rotational distances of any Honda
  7. This is easily, very effectively, and inexpensively corrected however
  8. Like all 70s Hondas, the horn is awkward-sounding
  9. The carburetors employ a messy, inconvenient through-the-screw float bowl drain system
  10. Like all 70s Hondas, the stainless steel front disc brake disc is designed to look good and not to stop good
  11. This can be mitigated somewhat and stronger braking achieved by using all-metal brake pads
  12. A lot of folks "recam" their rear brake panel to get more use, but this can result in dangerous lockup--don't do it
  13. A goofy lock-looking part was fitted by dealers to the gas cap under a required recall
  14. As with other vintage Hondas, this bike lacks the capacity to accept a lot of non-original electrical loading
  15. Despite the above, very small increased loads such as a quartz headlight will work fine
  16. Though inconsequential, all of Honda's 70s inline fours have alternators that do not charge at an engine idle
  17. Between 1969 and 1983 all of Honda's inline fours had this kind of charging system
  18. Replacing the CB500/550's intake manifold studs with bolts makes future removal of the carburetors much easier
  19. Virtually everyone adjusts the valve clearances incorrectly on these bikes
  20. Stock Honda control cables are vastly superior to aftermarket ones due to their overall quality and especially their Teflon lining
  21. Aftermarket charging system parts are very poor quality and largely responsible for diminished charging
  22. The CB500/550 and CB350F charging systems are adjustable for output
  23. The methods endorsed by user forums for testing electrical systems are archaic and inconclusive
  24. Vintage Honda clutches are virtually always misadjusted
  25. Most of the wiring harnesses in these 50-year-old bikes need to be replaced
  26. Electrical connector corrosion and melting is common but easily repaired and easily prevented
  27. Honda makes replacement electrical connectors available but it is kind of a secret due to their being listed in their tools bulletins
  28. Silicone brake fluid makes these old Hondas a lot more pleasant to own
  29. Very few of these engines are well-tuned, and similarly, most of these bikes are very poorly maintained
  30. When the engine oil level gets low, pressure drops to the camshaft resulting in damage
  31. Fast camshaft wear on SOHC fours is normal, with the CB350F wearing the fastest
  32. The engine rebuilding techniques advocated on user forums are hack, inexpert, and harmful
  33. Part of the above is due to forum engine rebuild advice being rooted in 1940s cast iron engine technology
  34. Using premium gas in 70s Hondas is ill-advised and can lead to excessive carbon buildup
  35. The availability of replacement pistons is not too bad, but quality rings are extremely difficult to find
  36. Even more difficult to get is proper cylinder machining
  37. As with all 70s Hondas, the SOHC four's valves are made to wear out by just 15,000 miles
  38. If you're smart you'll avoid aftermarket engine gasket kits
  39. If you're really smart you'll also avoid Allen screw kits
  40. 1970s Honda valve springs are the best in the world, many times better than aftermarket "racing" springs
  41. The CB500/550 engine positions its cam chain guide differently than in any other SOHC four Honda
  42. The CB500/550 cam chain tensioner frequently needs persuasion
  43. The CB500/550 and the CB650 are the only SOHC fours whose cam chains are adjusted with the engine running
  44. The CB350F is unique among SOHC fours in how it's cam chain is adjusted
  45. The CB350F cam chain tensioning system is a copy of the system used in Honda's CB360 twin
  46. Remanufactured stock-spec cams are popular and a good tactic when rebuilding SOHC four engines
  47. The standard SOHC four ignition system is one of the most difficult for DIYers to adjust properly
  48. A Dyna ignition is a good alternative, but it does not add performance and unlike the stock system it will eventually fail
  49. The CB500's transmission is very different from the other SOHC four transmissions
  50. The fitment of tapered steering bearings is not the best tactic; proper maintenance of the original bearings is
  51. The normal engine idle is 1000 to 1100 rpm; if this can't be achieved repairs or better tuning is needed
  52. Of the small fours only the CB650 has a primary chain tensioner, with the result some driveline snatch and potential rattle is evident
  53. This rattle can in most cases be eliminated through careful tuning
  54. The clutch basket driven gear can loosen on its rivets and add to this noise
  55. As with all vintage Hondas, installing aftermarket clutch parts reduces the performance of the clutch
  56. Some aftermarket clutch discs even damage the clutch basket
  57. After the valve recession problem, the biggest issue facing the SOHC four owner is rocker arm chrome peeling
  58. A crisis exists regarding this bike's carburetor needle jets and jet needles
  59. Not really a quirk, but the rear brake torque arm rubber washer on these bikes goes outside the arm, not behind it as many assume
  60. The CB500/550 is smoother than its bigger brother the CB750, but it is still a little rough-edged compared with today's more refined machines. And most of that roughness is perceived as buzziness. It's not overwhelming but it's there

Recommended reading:
The CB500/550 page
I like these bikes
Electrical deception
Cylinders done right
Engine assembly
sohc4.net
Valves and the CB500/550


Last updated January 2023
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© 1996-2023 Mike Nixon