Motorcycle maintenance 101

Cables

In order to avoid any cable ripping or sticking after every off road ride disconnect the throttle cable and remove the throttle from the bar. Clean the bar with some paper and rub grease over it. Put the throttle back, oil the throttle cable and the clutch cable using a special lube spray. You can find it in any motor shop.

Tires

Air pressure must be analyzed obsessively as the tires condition. Don’t wait until you fall down!
If the tire is flat (worn out), replace it! I know it’s expansive but it could mean the difference between 110mph knee down or knee out. Air pressure will be fitted to your riding style. For radial tires, lower pressure is used for aggressive riding and higher pressure for every day use. In diagonal tires it is the exact opposite because of the tire tendency to heat up. Higher air pressure helps the tire to stay cool by reducing the amount of inner layer movement and inner friction.

Drive chain

Your drive chain needs regular attention ever 300 miles because it is exposed to dust, rain and also subject to hard acceleration and very cool wheelies. You have to clean and lube it every 300miles and adjust its tension it when it gets loose.

Lubing your chain

Clean the drive chain with petrol, WD 40 or use a designated cleaning spray. After you got it cleaned up, lift the back end of the bike using the side peg, spin the wheel and spray chain spray on the inside of the chain. Wipe up the rear wheel and tire.

Adjusting a drive chain’s tension

Spin the back wheel and find the tightest point in the chain, then take a Tape Measurement place it on the swing arm and measure the amount of free movement. Loosen up the back wheel rod and use the pulling mechanism. Remember to pull both sides equally.

Wheels

Just remember after every off-road ride to clean and spray some WD 40 on them. using a 6mm wrench, knock on the spokes to check tension. If they feel and sound loose, pull them by turning them evenly about half a turn.

Battery

The idea behind the battery is making use of chemistry. Basically two led plates with sulfur acid and water between them. The acid is slowly entering the plates leaving only water between the two. The battery is constantly charged so the acid is returning to its place. The amount of acid in the battery is checked by a concentration gage. Due to evaporation, you may, from time to time, need to add water to the battery (distilled only), however, you should never add acid. Newer batteries are sealed anyways and they are gel (or nickel – just like your cellphone) based although the same principal applies to all batteries.

Brakes

Brakes are complicated to maintain and a lot of workshops just dont know how to do it right.
Paskal low: pressure =force*area of force. The pressure in both ends of the system (the master cylinder and the caliper) is identical, the area in the master cylinder is small so we should probably use more force in the lever.
Right? No! The lever moves almost half an inch but the brake pad hardly moves at all. The lever also uses a crane effect. It sounds complicated but it isn’t, trust me.
Now let’s replace the pads:
* open the two bolts that hold the caliper
* remove the pads
* using some white paper and brake cleaning spray, clean the pistons (they are already pointing outside)
* press them in using a wrench and the old pad
* clean the disk and the calipers pines using the spray.
* rub the pines with ATE grease (non oily)
* put the new pads in the caliper. Don’t forget any extra parts
* close the caliper with a torque wrench in 35 n/m
* take a can of brake fluid, open the brake fluid tank (on the bar) and the nipple on the caliper
* suck the brake fluid out of the caliper using a vacuum machine and at the same time add fluid to the tank
* When a fresh fluid starts to come out of the caliper close the nipple
* close the tank
* clean the system using only water
Brake fluid is the ultimate paint killer. Don’t let any on your paint. If some drips on your bike, immediately use lots of water and a clean towel to remove it.

Air filter

The best way to destroy an engine is to remove its air filter. Fresh sand and dust will cause an interesting effect inside the cylinder. Cleaning the air filter is a must after every off road ride and this is how to do it:
* First clean the air box area before opening it up.
* open the box and clean it from the inside using some fuel, then drain the tub that is connected to it from the bottom.
* Carefully remove the filter and clean its rails.
* wash it in some soap water and let it dry .
* lube it in an air filter spray or some engine oil.
* squeeze it a bit and put it back after rubbing grease on the sides for good selling.
* remember to close the box correctly.

Suspension

Basically if you want to stay in one piece while scrapping your elbows knees and ears, you have to adjust your bike and the suspension would be a good place to start.
Why?
A motorcycle is a light machine and as such is highly sensitive to road conditions and riding style. The bike has to be as stable as possible during your cunning stuns while running away from the cops. Think about it. A shivering platform is not very useful when you are being chased by a helicopter.
How?
There are 3 main adjustments for you to perform. Actually there are more but leave them to the pros.
Preload - Inside your front forks there are (how surprisingly) springs. In the back you probably already noticed it. Load your ass on the bike. Notice the sag. Now ask a friend to measure it using a meter. In a road bike the sag should be aprox: 20-35mm in the front and 5-12mm in the rear. offroaders should have more.
Compression damping - The rate of compression in the shock. To soften or harden it up just turn the screw on top of the fork. This will close or open the bleed hole inside. In order to further change the setting, you will have to open the fork and replace the metal shim inside.
Rebound damping - Controls the rate of the shocks return and is being adjusted at the bottom of the fork. Other settings ride-height,top-height,deck-height,oil thicknes ect'.

Carburetors

Every giser knows what carburetors are there for but not many know how it is build and how to adjust it.
There are two common carb types: flat slide and c.d.
Flat - The simpler type, the volume of air passing through the venture (the carb bore) is controlled by a throttle slide and the bore itself stays fixed. This carb is used in two strockers and race bikes.
Constant depression - The most common and is used in most of the road bikes. The bore is opening and closing by the engines manifold depression which is controlled by a butterfly throttle.
Tuning
Warning: do not try to tune your bike yourself. This could lead to engine failure. Excessively lean air\fuel mixer will operate as a burner and just burn the engine from the inside. Before you try to tune the carbs, please make sure the air filter is clean, the ignition system must is ok and the throttle cable is adjusted.
Tuning slides:
float height - The level of fuel in the float chamber .that effects on the amount of fuel that will drown from the main jet to the engine. Open the plug in the bottom of the float chamber and fit a plastic tube to it. Now lift the other end of it in the air and watch the fuel level. It has to be approx 1mm lower from the chambers gasket. If it is too low or high open the chamber and bend the float’s metal tang.
Pilot jet - Affects the low revs and way to adjust it is simply to find the point that engines revs are the highest. Than lower them using the idle rev screw and repeat the process
throttle valve cut-away - On modified carbs or engines there could be a problem of too much air in a case of sudden throttle opening. From idle speed, try enriching the pilot mix (the screw with the spring).
Needle and needle jet - The jet and its needle suffer from wear due to the fuel that flows through them. Simply replace them and adjust the needle by clipping it in the middle groove. You can work your way from there. The final tuning is performed according to the manufacture table and the engine’s emissions.
Tuning c.d.
is the same as slides in a case of multiple carbs you have to adjust them in synchronization by using a vacuum gauge.
Mixture screw:1500-3000rpm
pilot air jet:2000-5000rpm
needle:2500-8500rpm
main jet:7500-14000rpm

Most sport bikes today use fuel injection systems and combined with a computer based engine management system (like Dynojet’s power commander) to not require any maintains at all. Changing settings is a simple matter of loading a new map to the computer using your laptop.

Emissions

The shit that comes out through the exhaust is the most accurate indication about engine problems, carb adjustments, ignition problems and generally world peace.
The engine sucks air through the air filter and fuel from the gas tank.
They mix in the carb and become a mixture in 14.7:1 ratio. That means that when 14.7 kg of air enters the combustion chamber only 1kg of fuel had also entered.
This mixture is called ‘stochiyometric’ and it is used for cleaner combustion . For best performance we need to use more gas (13:1). lets explain a little about the stochiyometric Mixture:
the outside air has only 21% O2 and the rest is N2 (78%) and CO2 (1%)
the fuel in a good day is HC.
The emission:
what the problem you ask ? It’s very simple : O2 comes from the outside air, HC comes from the fuel tank, together they become CO2 and H2O right? Not exactly. The final emission contains HC, CO, O2, CO2, H2O and NOX. The last one is created only in high temp engines that means in all the new ones.

HC - fuel that didn't burn it is measured in ppm part per milion there reading is 50-350ppm
NOX - is created from the N2 in the air
O2 - oxigen that didn't burn (0.5-2%)
CO - is basicly co2 that didn't manage to find another o (0.5-2%)
CO2 - 13-15% and the bigger the better . it is the indication for a good combustion
N2 - does not effect the combustion (71%)

Source: galratner.com