Understanding the 2nd Hand Motorcycle Condition Before Purchasing and Starting Maintenance

The C90 Deluxe I happened to see in the garage of a fellow motorcycle enthusiast was a 1974 model, model C90K2, featuring the "seagull" handlebar shape. The seat and exhaust system had been replaced with new parts, but the motorcycle was equipped with genuine parts appropriate for its age, and its form was truly normal. The Super Cub C50/C70 of this era had two body designs: STD (standard type), which inherited the body of the previous generation model (with a separate fuel tank), and DX (deluxe), which had a new inner tank frame design. Each model also had a cell starter version, the "M". In order to understand the current condition of the vehicle, let's focus on the points that need to be checked first. It is important to note that this is not a check and inspection limited to the Super Cub, but is a common inspection item for both large and small vehicles.

First of all, go around the exterior.

A 1974 Super Cub C90K2 that had been replaced with a new exhaust system and a new seat. Even though the parts have been replaced, it is likely that the previous owner was very particular about having the right parts installed for the year. The liability insurance had expired, but it is obvious that the motorcycle was usually kept in good condition. When checking the tires, be sure to read the depth of the grooves, cracks in the sidewalls, cracks in the bottom of the tread grooves, and the year of manufacture marked on the sidewalls. The four-digit number in the oval frame is the year of manufacture of the tyre. If it says "3015", the bottom two digits "15" indicate "2015", and the top two digits "30" indicate the 30th week. In other words, it is the 30th week from the first day of the year, so the production is roughly in late May. Overall, it means that it was produced in late May of 2015. If the last two digits are "91", it was produced in 1991. It's not about the amount of remaining grooves in the tire, but older tires, even unused ones, definitely have degraded performance.

Rattles around the feet that affect the stability of the vehicle

If it's the front, it's the bearings that are the key to steering. In the rear, swingarm pivot bearings and bushings are the main points to check. If any of these moving parts are rattling or malfunctioning, it will greatly affect the handling of the motorcycle and become a symbol of how difficult it is to ride. A rattling stem bearing or a dented ball race will cause a significant drop in performance. When you turn the handlebars or change lanes, you will feel a strong sense of discomfort. Can you lift the front wheel with the main stand or some other method to free it, and can you smoothly turn the handlebars left and right? Does the handlebars move smoothly from side to side? Are there any snags or rattles along the way? You can also check for rattling of the stem bearing by pushing the tire with both hands and shaking it. You can also check the rear tire to see if there is any rattle on the swingarm pivot by holding the tire and shaking it in the same way.

Immediate inspection of the condition in the fuel tank

Pay attention to the condition of the gas tank, which can be checked immediately. A motorcycle that has not been ridden for a while often accumulates water in the tank due to the storage environment. Even if the motorcycle was stored indoors or in a garage, the difference in temperature causes condensation to form. It is not uncommon for that moisture to turn the inside of the tank red and rusty. You can check for rust by opening the cap, sticking your fingertip in, and touching the ceiling of the tank with your fingertip. You can also visually check the condition by smelling the fuel and peeking inside with the inspection lamp (the straightness of the LED lamp is perfect for pin spot checking).

Oil is more about contamination than quantity.

Before starting the engine, it is important to check the oil condition. It is important that the oil level is sufficient, but it is also important to check the level of contamination. Wipe down the filler gauge with a clean rag and check it. Since there is a possibility that the oil has been changed just before, it is important to check the condition of the inside of the filler gauge and the inside of the filler hole with the LED light just like the gas tank. If the inside of the engine is black and dirty, there is a big possibility that blow-by gas has entered into the crankcase for many years due to the decrease of compression pressure, wear of piston rings and valve guides. That is the cause of the pitch black dirt inside the engine.

Honda's old 90cc series had a lot of battery ignition.

Not only the Super Cub of the old 90cc era, but many models of the same age with the same type of engine use 6V managed battery ignition rather than flamag point ignition (AC coil ignition) like the 50, 70 and new 90. In other words, because the spark plug is ignited based on the battery power supply, if the battery condition is not good, the engine condition is definitely not good. Is there corrosion in the terminal? Is the level of the battery liquid OK? Check the condition first, and if you are not sure, replace the battery with a new one.

Headline 6

If the battery condition is good, you can check the operation of the lights. In the case of a battery ignition vehicle, all electrical systems are also controlled by the battery, so it is not possible to use the AC mains to power the headlights and tail lights at night as on a 50 or 70 model./It is not using AC power. After confirming that it lights up well by operating the switch, let's check the setting condition of each bulb. If there is a rattle when setting the bulb fittings, use pliers to bend the bulb socket and adjust the bulb fittings so that they fit snugly. If there is a lot of rattling, it is easy to break the filament by vibration.

After a thorough inspection, start the engine.

In the case of the Super Cub, various functions and parts are hidden inside the leg shields, so when starting the engine, the leg shields can be removed and work in progress to quickly access the malfunctioning parts. On older Super Cubs, the air cleaner element lid must be removed in order to remove the leg shields, but when checking the engine condition and test riding, be sure to close this air cleaner lid even after removing the leg shields. If you test rides the carburetor without the lid and set the carburetor, the data will be completely different from the data when the lid is installed, and it will cause a malfunction.

When you buy a used motorcycle, you can rest assured that you are buying a used motorcycle from a reliable motorcycle shop. However, nowadays, the private trading environment has advanced, and there are more and more cases where things, motorcycles, and motorcycles that were owned by private users until yesterday can be taken over and purchased as they are through online auctions and meccari. It's good if you can bring your personal vehicle to a familiar shop and ask for maintenance. However, there are some buyers who do not know what to do with their vehicles and continue to ride them in poor condition without maintenance, and as a result, they lament that their vehicles do not last long. Because the number of such users is increasing, motorcycle maintenance magazines like ours are conveniently used, and the number of users who look forward to this web maintenance section is also increasing.

For example, what condition is the motorcycle you bought in? If you know it and don't know it, you will judge the situation differently to own and ride it. Here, we'll lecture you on the condition check you should know and how to do it, at least before you ride the motorcycle or start the engine.

First, let's check if the tires rotate smoothly. By turning the front and rear wheels, you can understand the condition of the wheel hub bearings. You can also get a feel for the condition of the steering and swingarm pivots by grabbing the tire and shaking it in small increments, as shown in the photo. If these "key suspension" points are in poor condition, the motorcycle should be extremely difficult to ride, as it will be impossible to ride straight. It is also important to understand the remaining tire capacity and expiration date.

It is also important to check the fuel condition of a motorcycle that has not been ridden for a while or has been neglected. As soon as you open the tank cap, you can tell if the fuel has gone bad by the unpleasant smell. You can also feel the volatility of the fuel by touching it with your fingertips. "If you notice that something is wrong, or if it has been more than six months since you last filled up with gas, and the engine does not start smoothly, start by removing all the fuel and replacing it with new fuel. Be sure to check the smell of the rag and the color of the fuel when you do this. There are many cases that the residual fuel worsens the engine starting performance.

On the other hand, what should you do if you are not going to ride your motorcycle for a while? If you think you won't be riding for a few more years, remove the tank, drain all the fuel, drain all the gas in the carburetor, and turn the cell starter at full throttle for a while. Turn the throttle fully open and let the cell starter breathe in all the remaining gas in the carburetor passages. The tank cap should be opened and dried in the sun, and the inside of the tank should be completely dry before storing the motorcycle. If you can't do that, you can use fuel stabilizer to prevent fuel from deteriorating and start the engine. This product lasts longer than expected, so please try it when you store your motorcycle for a long time.

See HONDA Moto Index Page
See Accessories for HONDA SUPER CUB 90 (C90)
See Accessories for HONDA SUPER CUB 70 (C70)
See Accessories for HONDA SUPER CUB 50 (C50)