exhaust pipes

[dominiks3]

Hi all,

Maybe it will sound to you as a little dull question, but I'm wondering why some 4T thumpers do have 2 exhaust pipes and some have 1??

I know it has something to do with valves, engine effectiveness ect. Can it also be the simple matter of look?

Please explain ?

[latzayzf]

if it has 2 exhaust ports on the engine it meens its got 2 pistons if 1 its probleys just 4 show

[dominiks3]

What about Honda XR650R? One piston, 2 exhaust pipes, 2 exhaust valves?

Are there any other reasons?

[dominiks3]

Look at this NSU, two pipes and 2 valves in 4T...

[KaptainKoolz]

on the xr650....isnt the split header there because the down tube is right in front of it??....and if your talking about the crf250's dual pipes, it sopposedly creates more hp.....hmmm

[Fixitguy74]

It's all about exhaust flow. In theory the faster and easier you can get it to flow the more potential horsepower you can have. Honda's dual pipes on the CRF250 are suppose to create better flow without creating more noise (db) than a single pipe.

[Bama1]

i would just rather have one i see no need in buying 2 pipes for a single cyl. engine

[doodman]

Honda xr 200, 250, 350, 400,500,600,650's do because they are 4 VALVE heads. One exhaust pipe for each exhaust valve. Earlier year xr's have two carbs also.

[punga]

Honda xr 200, 250, 350, 400,500,600,650's do because they are 4 VALVE heads. One exhaust pipe for each exhaust valve. Earlier year xr's have two carbs also.

Many 4 valve 4 stokes only have one exhaust port. Also 5 valve Yamaha's have one exhaust port. And the XR200 was a single port.

[manson3161]

It looks cool but the price of one pipe is bad enough not to mention buying 2 pipes

[doodman]

Many 4 valve 4 stokes only have one exhaust port. Also 5 valve Yamaha's have one exhaust port. And the XR200 was a single port.

Yes many do, but Honda xr's have 2. By the way, the earlier 4 valve xr 200's had 2 exhaust outlets, see pic below.? nice try though.

not me or my bike

[dominiks3]

yes, the theory of Power is known to me. Of course the gas has to let go, but look at KTM 690 Enduro for instance, It has actually more hp than XR650R and yet only one pipe fot the same bore capacity.. am I right?