i heard the revving a cold engine messes it up, why exactly is this??
and why does my engine take forever to start when its cold outside???
i'd really appreciate helpon this coz i dont know too much about engines.
excessively revving a cold engine is not healthy due to the lack of oil circulation...when your bike sits for a period of time the oil settles and you should allow for the oil to be pump back up to the top of the engine before you really rev it hard...a good synthetic oil will help this cause it clings to the metal better than conventional oil...
If you're having problems starting it when cold and you don't know much about engines...then be sure you are setting the choke when it's cold. That's the knob sticking out of the left side of the carbs...pull it out before trying to start. You could also try turning the fuel valve to the "prime" position for a minute before starting, if the float bowls aren't full, then you're spending time cranking the engine just to fill them before there is enough fuel to start the engine.
...and as stated above, give the engine some time to warm up before reving too much. You need to get the oil circulating and allow the engine parts to come up to operating temperature. Cold engine parts are loose fitting, they are all designed to be run while warm.