Powervalve....what is it?

[PlatinumDogg]

I hear lots about powervalves....what are they..what do they do...????

[MTS]

powervalves are valves on the exaust port that close at low rpm for more torque and open up at higher rpms for more top end and a fatter power band..from what i understand..but i could be wrong..lol

[TrikeKid]

they're two stroke only as well.

[370banshee]

trike sucks is about right the only part he forgot is that most powervalves are engine RPM operated. and a rod moves it. it really regualtes back pressure and in turn changes how ans where the power comes on. also you have a smoother and longer powerband

[NICKG]

actually what they do is change the port timming and compression of a given engine. 2 strokes actually have more top end power when they have low compression and more low end when they have high compression. the idea is to allow for a wider powerband, this is done by varying the ports opening in relation to the piston and in effect the compression by the opening or closing of them. back when these trikes were new, it was not uncommon to see them pushed or pulled around buy a support trike to start them due to such low compression(especially on flattracks or tt courses). of course motocross trikes ran high compression for better low end power, and the flat trackers low for high end power(where you just basically run wide open all night) look at the way that most manufactureres qoute compression on modern 2 strokers(like a cr250) they will give low rpm compression and high rpm compression

[AZ250R]

I hear lots about powervalves....what are they....????

Something else to go WRONG!