Once you've returned your city runabout to its former glory with a thorough clean and polish, it's time to check the basic functions and components and make sure everything is working properly and road-safe – maybe you noticed a few things that need attention while you were cleaning:
Check your tyre pressure (refer to your vehicle manual). The correct pressure is usually 1.5-1.8 bar at the front and 2.0-2.2 bar at the back.
Check your tyre tread depth – the legal minimum is 1.6 mm, but to ensure safety on wet roads, you really should think about replacing tyres once they reach 2 mm.
Check the condition of your brake pads. On a disc brake, check the wear indicator groove on the pad. If it is no longer visible, you need to replace the pad. This also applies if any part of the pad is below the minimum thickness of 1.5 mm. Drum brakes generally have a pointer on the brake lever, or otherwise you can tell the state of the brakes by the setting of the brake rod or the cable control adjuster, or by looking inside the drum itself.
Check the brake discs – are they badly worn (clear recess at the edge) or do they display deep scoring? Scoring impairs the efficiency of the brakes, while brake discs that are worn beyond the service limit will run hot and must be always be replaced.
Check the battery – does it need topping up with distilled water? (does not apply to maintenance-free batteries). The battery is located underneath the seat, or in a compartment of the front fairing, or in the step-through area of the scooter (check your vehicle manual).
Check the oil level and, if your scooter is water-cooled, the coolant level.
Additional maintenance jobs
You should read your vehicle manual thoroughly to familiarise yourself with the maintenance intervals recommended by the manufacturers for your scooter, or ask your local retailer.
Have you noticed any leaks coming from the engine? If so, it's best to get a vehicle workshop to check it out - scooter engines only have a small oil capacity, so any loss of oil can soon result in engine damage! Are any of the brake hoses cracked, brittle or damaged? If yes, you should definitely go to a professional mechanic. Are the control cables still in good condition, or are there breaks in individual wires? (if yes, replace cable). Do any of the cables or levers need to be adjusted? Any sign of rust on metal parts? The quicker you get on top of rust with sandpaper and paint, the better! Have vibrations caused any of the mounting brackets to show signs of cracking? If you've discovered the problem early enough, it may be possible to repair it adequately with a simple spot weld. Are all screws securely tightened? If any screws are rusty, it's best to replace them. Are all lights working properly, including the brake light, or do you need to replace any of the bulbs?
Particularly if you have a two-stroke scooter, you should check the level in the two-stroke oil tank every time you stop for petrol. It may be too late when the oil level indicator lights up, and riding without oil will very quickly damage your engine! To prevent such damage, the ignition is automatically switched off on some scooter models when the warning light comes on. Only use two-stroke engine oil specially formulated for scooters/motorcycles. Four-stroke engines also require the occasional top-up, so it's important to remember to check the oil level every now and then. Only top up with motorcycle four-stroke engine oil (check your vehicle manual for the correct oil type).
As with any car or motorcycle, you should always replace the brake fluid in your scooter's hydraulic braking system every two years because even in a closed system, the fluid absorbs water over time, which means you may no longer have a reliable brake pressure point when the brakes are hot. All work on your brakes directly affects the safety of your scooter, and brake fluid can damage your paintwork, so you should only change the brake fluid yourself if you are an experienced DIY mechanic. You will find more information on this topic in the relevant section of our DIY tips for motorcycles. If the hydraulic brake no longer has a defined brake pressure point when stationary, e.g. the brake lever can be pulled right back to the handlebar, there is something wrong – you probably need to bleed the brakes. Please check with your local motorcycle workshop.
You can easily check the air filter (see Fig. 7), which should be carried out approx. every 2,500 miles. A blocked air filter not only reduces road performance, but may also allow dirt into the scooter's fuel supply system, causing the engine to run irregularly or causing start-up problems. If this happens, cleaning the carburettor or fuel injection system is a time-consuming job. The air filter is located either behind a side fairing or in a box near the scooter's variator. If it is made of foam and is undamaged, it can be washed in water with a little dishwashing liquid, then lightly lubricated and placed back in the box. Paper filters will need to be changed.
Best in test
You should also change the oil and oil filter of four-stroke scooters approx. every 2.500 miles (see Fig. 8). First run the engine warm so that the oil will drain out more easily. Stand your scooter on level ground, place a plastic sheet or cardboard underneath the vehicle and an adequately sized drain pan underneath the engine, and open the drain plug so that the hot oil can flow into the pan. When the oil has completely drained, clean the drain plug and the sealing surface on the engine and reinsert the drain plug complete with new seal. Tighten the drain plug with care, as you don't want to strip the thread in the aluminium engine case! Now push the drain pan underneath the oil filter housing and remove the filter (see Fig. 9) – make an exact note of the mounting location of the individual components. A little remaining oil will drain out. If your scooter has a sieve filter, clean it with brake cleaner. Disposable filters must be discarded. Insert the oil filter plug with a new seal in the reverse order (seal is included in cartridge filters) (see Fig. 10), taking care not to damage the thread. Now fill the engine with the prescribed type and quantity of four-stroke engine oil (see Fig. 11). Run the engine, make sure the scooter is standing straight and on level ground, and check the oil level again through the sight glass or using the dipstick. Check the old, drained oil for metal deposits – if you do find any metal fragments, ask your vehicle workshop where they have come from in order to prevent any serious damage. Dispose of the oil at your local recycling centre or Louis store.
If you have a two-stroke engine, you will not need to change the engine oil. However, the two-stroke oil pump is essential for the separate lubrication of your engine and you should regularly check that it is working properly if it is cable-controlled, i.e. operated via a two-part throttle cable. To get to the oil pump, remove the side fairing of your scooter and/or storage compartment – in some cases, you will also need to remove an air baffle. The oil pump is fitted with a cable pulley, which should respond as soon as the throttle twistgrip is turned. There must not be any play, as this would mean that the oil pump is not working synchronously with the carburettor, and thus temporarily failing to supply oil to the engine.
There are usually markings on the oil pump housing and the pulley. If the oil pump cable is correctly adjusted, the mark on the housing must line up with the mark on the pulley when the throttle twistgrip is fully open or fully closed (depending on model). Because the throttle cable tends to stretch over time with use, you will need to re-adjust it every now and then. Take care not to overtighten the cable pulley – this would cause your scooter to burn too much two-stroke oil, which would result in rapid carbon build-up (coking) in the exhaust port and exhaust system. It goes without saying that correct adjustment is only possible if the throttle cable and the twistgrip are working properly. The twistgrip should always automatically return when you release it. The play between the twistgrip and housing should be 2-6 mm (mark with chalk if it helps – the cable can be adjusted at the throttle cable adjuster), and the cable must not be under tension at full lock. Replace fraying cables immediately.
There is often a flow filter between the two-stroke oil pump and the engine, which also needs to be replaced at specific intervals or when it is visibly soiled. To do this, use a hose clip to interrupt the oil flow. Pay attention to the direction of flow when installing the new filter, and make sure that there are no large air bubbles in the filter. Irrespective of whether you have a two-stroke or four-stroke scooter, you need to regularly change the oil in the final drive (see Fig. 12). Refer to your vehicle manual for maintenance intervals and oil type – you'll find practical small bottles of special scooter gear oil at your local specialist retailer.
To change the oil, put your scooter on the centre stand on a level surface and thoroughly clean the final drive around the filling plug and drain plug. Drain the usually small amount of oil into a container via the drain plug, clean the plug and re-insert complete with new seal. Gently tighten the plug in the aluminium housing. Now top up the drive with new oil via the filler plug. If your scooter is not fitted with a level probe, fill the oil to the upper edge of the opening and re-insert the clean plug complete with new seal. Check the oil level again after a test drive. Dispose of the old oil at your local recycling centre or Louis store so that it cannot pollute the environment. If you detect any leaks coming from the drive, take your scooter to your local vehicle workshop, as any loss of the already small volume of oil may end up damaging the engine.
You should change the spark plug every 5,000 to 7,000 miles to ensure good road performance and problem-free start-up. On some scooters, you will need to remove a cover or the luggage compartment to get to the spark plug. Wait for the engine to cool down before attempting to change the spark plug and always use the correct size plug spanner (usually in your travel tool kit). Make sure you don't let any dirt fall into the engine while you're working – if the spark plug is in a deep shaft in the cylinder head (4-stroke engine), it is best to clean the shaft with a vacuum cleaner before you remove the spark plug. Only use spark plugs recommended by the manufacturer and check the plug gap with a feeler gauge (refer to vehicle manual). If necessary, bend the central electrode carefully to adjust the gap.
At longer intervals (approx. every 10,000 miles) check the valve clearance if you have a four-stroke scooter. Only attempt this task if you are an experienced DIY mechanic – if in doubt, go to your local motorcycle workshop. You will need to decarbonise (decoke) a two-stroke engine at roughly the same intervals because over time, the two-stroke oil burning in the combustion chamber leaves carbon residue on the exhaust port of the cylinder and on the piston crown and cylinder head – particularly if you do lots of short runs. After an even longer period, the inside of the exhaust will also be coked up, All this can considerably reduce road performance. If your scooter isn't pulling, it's time for a thorough decoke. To do this, remove the exhaust from the engine. Then move the piston to TDC (you can either observe this through the exhaust port or use a TDC finder) and take off the cylinder head (undo screws in diagonally opposite sequence). Make sure that the cylinder base gasket remains tight – if there is a gap between the cylinder and the seal, you will need to replace the seal, which means dismantling the cylinder.
Use a scraper or wire brush to remove any carbon deposits from the piston crown. Avoid any bits of carbon getting into the crankcase – it's best to suction them up with a vacuum cleaner. Then move the piston down so that the exhaust port is free, wipe the cylinder lining clean and use a screwdriver to scrape any carbon from the exhaust port and exhaust pipe flange. Clean the cylinder head with a wire brush. After you have thoroughly cleaned all parts, lubricate the cylinder walls with a very thin layer of two-stroke oil and refit the cylinder head and exhaust complete with new gaskets. Tighten the cylinder head screws step-by-step in diagonally opposite sequence. If you're not sure about delving into the inner workings of your scooter like this, it's better to leave this job to the professionals! Generally speaking, you will need to replace an exhaust that is heavily carbonised after long use – only classic scooters are sometimes built so that you can open the exhaust and burn off the deposits. However, this is not without dangers and, whatever you do, never try and burn carbon deposits off a modern, single-piece scooter exhaust!
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These tips for DIY mechanics contain general recommendations that may not apply to all vehicles or all individual components. As local conditions may vary considerably, we are unable to guarantee the correctness of information in these tips for DIY mechanics.
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