a 2-stroke engine has no exhaust or intake valves built into the
engine, unlike a 4-stroke, where these valves, usually in a pair or
two pairs, are located above the piston. effectively, a 2-stroke
engine's piston acts like a valve, blocking the exhaust or intake
ports as the piston oscillates.
the valve that people usually talk about on 2 stroke bikes is the
"power valve". read that one example of this is the exhaust power
valve. the power valve acts to "open" at certain rpms, giving that
added "kick", hence "power valve". maybe someone else can give a
more comprehensive explanation.
well technically it is still a valve, but it differs that in
4-strokers, it's a cyclical, continuous operation actuated by cams,
lifter arms, the works, where as a 2-stroke's
valve opens at certain rpms only.
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rock hard... ride free...
[This message has been edited by l3stat (edited 09 April
2002).]
