This should be checked while the tyres are cold and the engine switched off. Check the pressure of the tyres against the recommendations found in your user manual or by your Dealer. Inspect the tread for wear and embedded foreign bodies (such as glass, sharp stones, etc). Check the the slack in the driver chain lower run midway between the sprockets- this should be niether excessively tight or loose. If necessary, lubricate the chain with oil or grease recommended by your Dealer, wiping off any excess. Also check the wheel rims for any damage or irregularities.
With the engine switched off and your bike off it's stand, test your front and rear brakes by applying pressure onto the brake levers or pedal. Ensure that there is the recommended amount of play in the levers, and that there are no fluid leaks.
Test your front suspension by applying front brake and compressing the front forks 2-3 times. Inspect for any damage, leakage or burst/loose seals and fittings. Look at your rear swing arm and check for worn swing arm bearings. Sit on your vehicle and test the rear shock absorber by 'bouncing' gently a couple of times. Again, inspect for any damage, leakage or burst/loose seals and fittings.
Make sure your key is in the ignition first- check that the headlight, indicators, horn and brake/rear lights are all working.
Firstly, always keep your fuel tap set to 'OFF' when your vehicle is not in use, and be careful not to switch onto reserve useage instead of the main reservoir when operating the tap. Check the Fuel lines for any signs of leakage or deterioration, and make sure the pipes are not pinched or blocked in any way. Also make sure you have enough fuel for your journey. Make sure your vehicle is level (i.e not on a side stand) and in a neutral gear if applicable, and start the engine, letting it idle for a couple of minutes (and even longer in cold weather): this lets the engine oil lubricate all the engine's internal workings.
To check the oil level stop the engine and let it cool for at least 3 minutes. Remove the oil dipstick (located as per your user manual) and wipe it with a clean rag. Again making sure that the vehicle is on level ground, reinsert the dipstick into the plug and then remove it- the correct oil level should be displayed. If your level is low, add more oil as required.
Try to avoid mixing oil (consult your Dealer for the best kind), and never ride your vehicle with insufficient oil.
Your throttle should be smooth and return to full close on release. Once your engine is warm (see 'Fuel and engine'), test opening and closing the throttle- without 'revving' excessively. If your throttle action is not smooth, add lubrication to the throttle cable (see your Dealer).
For vehicles with a hand clutch (Twist and Go scooters and motorcycles aren't part of this), check that the clutch is working properly and that there is the recommended amount of play in the levers. Inspect for fluid leaks and ensure that the cable is properly secured in it's clamps and clips.
For vehicles with a manual choke, check for smooth transition when using the lever and add lubricant if necessary. Avoid leaving the choke on for prolonged periods of time, as this can flood the engine.