Dirt Bike FAQ

If it's that very smooth plastic, you'll have to sand it down, then paint over it with spraypaint made for plastics.
if you don't know what spraypaint this is, go to a local hardware store and ask of the workers.
if it's older and rough, make sure get it evened out.
either way,
-sand til you have a smooth sanded surface.
-paint with whatever is given to you by Mr. Home Depot or where ever, there'll probably be a primer and a few coats to make it look good.

Are your talking motorcycles or bicycles?

You might be able to find someone to give it to you ,if you have something you have to give away - say a toaster, someone will come pick it up and then you can put out the word about what you are looking for ,,,,

http://www.freecycle.org/display.php?region=Canada

they have groups in different cities in Canada - around the world- I read about on Yahoo!

There are simple hour meters that can be installed on dirt bikes by merely wrapping a wire around the spark plug wire that tracks the firing of the spark. I install these types of meters on all my bikes before they leave the shop (when purchased new) or installed upon picking up (when I buy used).

these usually record to the tenth hour and are relatively inexpensive.

http://www.cyclegear.com/spgm.cfm?L1=&L2=&L3=&L4=&item=TUC_21-1903&tier2=3039

Exhaust from the dirt bikes exits and the heavier partials, unburned oil partials, fall into the dirt. The rubber tires have a reaction with the oil making them slightly blue. So the answer is the oil in the dirt.

Usually, dirt bikes have fenders high above the tires, tires are knobby, most don't have lights.
Street bikes have fenders close to the tires, tires are smoother, and have headlight, taillight, turn signals, horn, and mirrors.

The valves are only an issue on the crf250r. A lot of the subtle difference are just that. SUBTLE. But MotorcycleUSA has some great reviews on youtube. Also magazines and websites like TransworldMX and Dirt Rider have great reviews. Pick a color. (Stay Japanese)

Probably the BSA DBD 34 Gold Star. or contemporary 500 Matchless, because in Scrambles trim both were hitting 100 mph in UK scrambles meetings on mud on Knobblies on short tracks in the early 1960s which was mad and caused the rules to be revised to restrict race speeds to an average of 30 mph and led to the steep climbs and jumps of today. Desert Racers again where do dirt bikes stop and desert racers start becuase Arabs were riding at nearly 200 mph on courier duties across the desert during the Gulf wars.
The bike shown above is not a dirt bike because it has street tyres, and lets face it , the only difference between old style dirt bikes and contemporary road bikes were the tyres.

Go to a local automotive swap meet if you want to find one cheap
used gas ones go for around $200

It'll run worse because you''ll lose back pressure. And upset the neighbors, who'll petition the law to have dirt bikes banned.

Well done.