The basics of motorcycle maintenance

Nowadays a visit to the service station with your bike is like visiting a doctor – they do not believe you unless you walk in with the same symptom more than twice.

Many riders out there take their bikes apart in order to service them, many do it out of passion, while some do it to avoid a downward spiral into debt. Maintaining a bike may on a few occasions get heavy on the pocket, but nevertheless is an essential part of owning a motorcycle. BI’s Raymond Raj looks into the basics of maintaining a Honda Unicorn.

Give the engine some Lubrication
The phrase “God is in the details” suits the oil-changing process perfectly. Changing your bike’s engine oil sounds very simple but even experts goof up sometimes. If you want to keep your engine running well, change the oil often; it is simple – provided you do it right.

The oil drain bolt will be at the bottom or at the side of the engine. Make sure you place a container large enough to hold all the oil below the drain bolt. Draining the oil is best done when the engine is hot, but if it is way too hot you can get a nasty burn, so wait a while and let it cool down a bit. Using a proper size wrench, open the bolt and let the oil flow into the container. Once you have the bolt out, inspect it visually to get rid of any metal particles that are stuck to it. Tilt the bike a little so that every last drop of used oil flows out. The oil filter is to be changed at every alternate oil change, as it filters the oil of any unwanted impurities.

Once the engine is drained refit the drain bolt. Ideally, you should use a torque wrench to do this, but even if you use a correct size wrench, make sure it does not slip. Using a funnel pour in the specified quantity of new oil through the dipstick opening at the top. The oil level can be checked by using a dipstick; some bikes also have a glass window. The level of the oil should not be more than the specified quantity, closer to the maximum mark on the glass window and the dipstick. Since we were using a Unicorn it requires one litre of oil. When checking the oil level with a dipstick never screw it in, just dip it and remove to check the level. Recap the dip stick and you are done.

CAPTION
1] Unscrewing the oil drain bolt
2] Draining the dirt and engine oil
3] Checking drain bolt for any metal particles stuck to it
4] Refilling with new engine oil of specified quantity

Keep your carbs checked
The thought of overhauling or draining the carburettor can instigate fear in many. To drain and clean the carb, empty the float before you turn it over to avoid the fuel from attacking the diaphragm. Spray the carb with brake cleaner (make sure it is rubber friendly) or with normal air from the compressor. Undo the tops’ screw without it slipping and watch out for little O-rings under the tops that help in sucking in air. Check the diaphragm for holes and also make sure the needles are evenly tapered. Do the same for the float chamber screws.

Once this is done, remove the pilot and main jets with a well-fitting screwdriver. These jets are very small and even a little speck of dirt can reduce the jet size. Blow clean them, as well as the emulsion tubes, with aerosol or compressed air. If the jets are very grimy soak them in brake cleaner.

The air mixture screws are tiny and tricky to handle. There is a default factory setting for these which you should return them to while reassembling. Screw it on until it is seated and remember the number of turns as a point of reference for re-fitting. Get the O-rings out too, which are at the end of these screws. Now that all the jets, screws, and O-rings are out you can go at it with an air-dust remover to get rid of any last traces of grime. Do not use pins or wire brushes on the jets.

CAPTION
Carb can be drained by loosening the screw to drain out dirt and fuel

Batteries
With many motorcycle companies opting for self-starters these days, a lot of emphasis falls on the batteries, which are mostly way too small for the kind of work they are required to do. A battery
will discharge slowly, one per cent of its charge per
day if it is left alone not doing anything. A battery should be charged till it is gassing freely.
Add distilled water to the battery if the level is low. You will need to unscrew the caps on top and fill the water evenly in all the wells. Keep in mind not to overfill it with water as while charging it will overflow and mix with the acid causing harm to your bike. Plug the charger and connect the terminals with correct polarity being achieved, positive to positive and negative to negative. Interchanging the terminals will result in the draining off of the battery of whatever charge it already possesses. Plug the charger to the battery and charge the battery at one-third its rated capacity in A-h for 5-6 hours for a full charge.
There is a trick to make an almost junk battery that does not hold any charge, work. Add one-fourth of a teaspoon of magnesium sulphate (Epsom salt) to each cell. This works 60-70 per cent of times; it will get you through for the 2-3 months of winter. It won’t hurt the bike as the battery is already junk.

CAPTION
1] Connecting the battery with wrong polarity will drain it 2] Battery should be charged with correct polarity 3] Topping up the battery with distilled water

Changing the chain and sprocket
A chain and sprocket comprise the final drive delivering power to the wheel. A shagged chain and a worn-out sprocket will rob you of precious horsepower and fuel.

First you need to know to what extent the chain is worn out. If by pulling the chain on its way out you are able to expose more than half a tooth of the sprocket it is time to change them.

Remove the front sprocket cover and remove the clutch actuating mechanism to gain access to the sprocket nut. Clean and degrease the dirt. Before you loosen the rear sprocket nuts put the bike in gear and ask a friend to hold the brakes. Do not loosen them too much as they will hinder the wheel turning. Now wedge in the lock washer and loosen the front sprocket nut. To remove the chain, visually locate the chain lock and open it. Once the chain is off, remove the rear wheel and the rear sprocket, which is usually bolted to the rear hub.
If the bolts are corroded clean the grime
that you see.

While refitting the new sprocket be sure you bend over the locking tabs if there are any and as for the chain, the closed end of the chain lock should be in the direction of chain motion. When you have everything in place tighten the bolts, and before refitting the front sprocket cover adjust the clutch actuating assembly. Lube the chain and take the bike for a short ride, after which the chain will stretch (all chains tend to). Re-adjust the chain slackness
once back.

Also keep in mind to never over tighten the chain as it will adversely affect the gear box bearing, wheel bearing and also the fuel efficiency. Ideally, there should be 10-15mm slack in the chain when the bike is off the stand and loaded or with the rider seated on it.

CAPTION
Chain tightening and slack adjustment