We get to work on the CX500 Eurosport and the carbs are, in a word ... shocking! The bike has a good spark so were half way there but these vacuum carbs are proving to be completely gummed up with what must be years of neglect. A carb gasket set has been acquired but the carbs are simply clogged to within an inch of their lives! I am not sure we can clean them, after days in the ultrasonic we will soon find out whether it is repair or replace!
The beautiful Honda CX500 Eurosport
It's got potential if you don't look at the seat!
The carbs have stood for a long time so off they come.
What is it about air boxes on old Honda's, there always difficult to remove!
We are lucky to find this tired but very sound CX500E commonly known as the "Eurosport". Our second CX this one is certainly still flaunting her flair, funk, and flamboyance even in her latter years!
The Honda CX500E Eurosport, produced from 1982 to 1983, was a sportier evolution of the original CX500. Powered by a 496cc liquid-cooled V-twin with shaft drive it offered around 50 hp and gained praise for its reliability and unique engineering with its longitudinal engine and twisted crankshaft. Upgrades over earlier models included triple disc brakes, alloy wheels, Pro-Link suspension, and a modernized frame for improved handling. Though overshadowed by inline-fours of the era, the CX500E developed a cult following for its durability, comfort, and distinctive style, making it a favourite among riders and custom builders even decades later. Although the bike is not yet running, we bought her as a non runner, she has a good spark and the engine turns over smoothly. Fuel appears to be the problem with a clogged up leaky petcock and nothing getting through the carbs it shouldn't take us long to get her purring again!
1
Nov
2025
Carburettor trouble ... again!
After a lot of fiddling and no shortage of YouTube watching we get the carbs back together but with no luck for the bike starting. After a bit of investigation we appear to have a spark but no fuel, now these carbs are vacuum ones and to be honest we were all a bit in the dark about how they worked, turns out the problem, possibly just the first one mind you, was the main fuel inlet was blocked (see image). This is a deep 90 degree bend into a very small pin hole, it was covered in green gunge. Off to the ultrasonic for a day and eventually after some hours and a few attempts at prodding with some copper wire (see the amount of gunge that came out on the micro fibre cloth opposite) we get her free.
For those tackling a similar job you will need to take the main inlet off to remove the carbs, fortunately this has a rubber seal.
27
Oct
2025
We get busy on our Honda CX500 and it is a better base than we expected on purchase :)
The airbox was reluctant to come out but was "persuaded" shall we say, the petcock was bought to fit but is slightly different, we will see how that goes and the carbs come apart where we find a sticky mess. Trying to get them back together again is no easy matter but we have a spare set for guidance.
