Honda’s Cub Series has been in production for over fifty years. The easy-to-ride, nearly unbreakable Cub and Super three wheel motorcycle
have provided practical mobility to over 60 million people, making it the most popular motorcycle ever built. Reliability is among the Cubs greatest virtues. Three-time World Champion road racer, Kenny Roberts said, "They were bulletproof." That’s good news for Honda Cub mechanics. This is not a quirky bike. They seldom need anything more than a tune-up.
Motorcycles tend to be seasonal vehicles. Long periods of sitting have predictable affects on any engine and are exaggerated on small engines. For it’s amazing reputation, the three wheel motorcycle is not immune to fuel problems. Allowing fuel to sit in the Cub’s gas tank and the float-bowl of the carburetor can cause the carburetor to get gummed up. Or if the fuel evaporates, it can leave a lacquer-like residue. If your Cub won’t run and it’s been sitting for several months or more, you may need to clean and rebuild the carburetor with a a rebuild kit. Rebuild kits are readily available.
Another common problem encountered by the cargo tricycle is air restriction. To run, your Cub has to have the right ratio of fuel and air. If your carburetor is working properly, your problem is probably air or spark. The fix here is easy. Get a new air filter. If you ride on a dirt road and anywhere that will expose the engine to dirt and dust it will need to be replaced more often. Some Cub owners replace their filter with a higher flow permanent filter which only needs to be cleaned, never replaced.
The Cub’s ignition system is about as simple as they come. You’re not likely to have problems with anything but the battery which is always prone to being drained or dying altogether. If you don’t ride your Cub regularly, it is especially hard on the battery. The best thing you can do is buy a "smart charger"---a kind of trickle charger that will top off the battery, then stop charging when the battery is fully charged. You can attache a lead from your battery terminals and hang the lead out from under the seat so it is easy to plug in and unplug. This is one of the best things you can get for any Cub that is ridden any less than daily.
When people think Cub, the older Classic Cubs come to mind. Old or new, passenger tricycle electrics are particularly prone to damage from the elements. Electrical connections can oxidize over time. Vibrations can wear through electrical insulation, causing short circuits. While connectors are easy to clean with some solvent and fine steel wool, if your Cub’s electrical components look worse for the wear, consider replacing rather than repairing them. The engine will last almost indefinitely. If you replace your electrical components when they act up, your Cub may last indefinitely too.