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4-2-1-2 exhaust

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ratranger:
This might be pointless, i.e. no benefits, but has anyone ever done what is basically a 4 into 2 pipe with a crossover or x pipe after the 4 into 2 merge?  The bike I'm working on will look better with a pipe on each side, and I'm leaning away from 4-4 because it doubles the muffler costs, and 4-1 would either leave a hanger unused which I would prefer to not cut off.  It's a slimline featherbed frame from norton.

jgger:
79 CB, and others, has a 2 into one on each side. But the 650 exhaust is not compatible with the 750 engines. The 650 is straighter up than the 750, it is closer to the 500/550.  Look up a stock 79 650 picture to get a visual.

carnivorous chicken:
Not sure I get this -- why not just a regular 4-2?

scottly:
Here's an example of an aftermarket 4-2 exhaust on a 550; there are similar systems for 750s.

ratranger:

--- Quote from: carnivorous chicken on January 10, 2026, 05:21:57 PM ---Not sure I get this -- why not just a regular 4-2?

--- End quote ---

 I'm going to have to make my own pipes due to not using the stock frame.  I know V6 and V8 engines benefit from an X or H style crossover between the banks, and with inline 4s a 4-2-1 style has benefits.  So I was curious if anyone had ever messed with doing a setup on these with cylinders 1-2 and 3-4 paired with a crossover between them.  I also know that it might not be done for packaging reasons, cost, or it doesn't provide any benefits.  So mainly asking to see if anyone else had tried it.

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