Intake Manifold Shorter VS Longer

[circleball]

A shorter intake manifold will be leaner (less gas) than a longer intake manifold, richer (more gas)

(i had been curious and found nothing on the matter in plain, easy, straight forward answers. So here we go.)

for example: if you have the smallest jet you can find and already tuned the carb with the needle (if you have one of those carbs). and you are still a bit rich on the mixture, try using a shorter intake manifold, and vise versa.

 

[crassius]

only thing I know for sure about manifold length is that if your engine vibrates a lot, a longer manifold will foam the fuel in the carb bowl & make the engine sputter

 

[biknut]

A shorter intake manifold will be leaner (less gas) than a longer intake manifold, richer (more gas)

(i had been curious and found nothing on the matter in plain, easy, straight forward answers. So here we go.)

for example: if you have the smallest jet you can find and already tuned the carb with the needle (if you have one of those carbs). and you are still a bit rich on the mixture, try using a shorter intake manifold, and vise versa.

Who told you that? The length of your intake manifold won't effect the jetting much, but it will have an effect on your powerband.

 

[maniac57]

More volume in the intake tract usually helps low end power and smoothness in small piston port two strokes. It seems to give a ram air effect when the air column slams into the closing port.
Bigger/longer intake=better low end.
Unless the engine is highly tuned this is a good rule of thumb.

 

[bairdco]

i've always found that the shorter the intake, the faster your bike goes, plain and simple.

 

[F_Rod81]

I prefer the shorty intake... Most of the aftermarket intakes that are sold now have a spiraled plenum. They atomize the fuel charge better and the result is a smoother, faster running engine. Plus they just look cooler then the stock manifold!