When the piston first uncovers the exhaust port the exhaust leaves with tremendous pressure. This bang creates a shock wave that travels the length of the pipe, through the expansion chamber, until it hits the stinger end of the pipe. Because the pipe is so constrictive at the stinger some of the shock wave gets reflected back towards the exhaust port. It takes a certain amount of time for the shock wave to travel to the end of the pipe and back again. It also takes the piston a certain amount of time to move down from the point where it uncovers the top of the exhaust port window until it covers it completely back up on its way back up to compression. Because the shock wave travels at the speed of sound the only way to change the length of time for the round trip is to lengthen or shorten the pipe. By tuning the length of the pipe to match the timing of the exhaust port and speed of the engine (RPM) you can achieve this super charging effect. Because you cannot change the length of the pipe or the amount of time the exhaust window is open while you are out riding the only variable you have to work with is RPM. When the RPM is correct for the port timing and pipe length you will be in the power band. On some engines, depending their set-up, you can tell when this super charging effect happens. This is sometimes referred to as being “on the pipe.”

 

lol, shav, very impressive. from what i understand the same concept applies to 4-strokes as well, (slightly different due to the lack of a "stinger" end of the pipe)

 

this hit is better than watching Bugs Bunny for myself

 

sweet link man

 

I personally like the yellow power bands. I used to have orange but they were as good as the yellow. I want to try some pink ones now[img]i/expressions/face-icon-small-wink.gif[/img][img]i/expressions/face-icon-small-smile.gif[/img][img]i/expressions/face-icon-small-wink.gif[/img]






jp

 

i've found the blue to work best. the pink ones r nice, but the blue one rips. it might also depend on what bike you have. but when you upgrade ur powerband, u gotta get the high compression lug nuts, otherwise it wont work as well.

 

Thats what happen when you work around them all the time.
Anything else you need to know about your 2 stroke?

 

Hey Shavo Heres a Q my shee isn't running like it should the carbs aren't set right how do i adjust them for the best performance? It smokes when i first start it up(due to being cold i think) then smooths out after it warms up but still smokes and the Throttle Responce is Kinda slow. i was beat by a 500 Scrambler and a 400 Scrambler.What do you think? any Advice would help.

 

bahahahaha. thats great! i got to try that

 

Any 2 stroke, no matter how well built is going to smoke and run like crap until it gets up to tempature. Sounds to me like your jetting is going to be the first place to start. Excessive smoke and bad throttle responce is usually a sign on a rich condition. Have you noticed where it is happening at, high or low end? The main jet is what controls your throttle from about 3/4 to wide open. If in fact you are rich then you should drop a size and see if it makes a difference. If it helps, but isn't quite right then drop another size. Just remember to do plug checks along the way to make sure you don't lean it out to far. If it's happening just after idle and through the mid range then your pilot jet size should be increased or your needle clip should be droped a notch, raising your needle.

Hope this helps
Shav0