Modifying the stock exhaust

I am currently building a cafe style bike based on an XS400 with my son as his first bike based on the bike pictured below. We've already modified the rear geometry by moving the rear shock upper mount points onto the fame rails approximately 3 inches lower than the stock mount points effectively raising the rear an inch or 2 and installing mount points for an adapted 92 FXR 600 rear set. I'd like to avoid the extra cost and noise associated with a 2 into 1 exhaust but would like to modify the factory exhaust as a more up-swept exhaust somewhat similar to the picture below, but on both sides. The problems I see include eliminating the crossover pipe between the 2 exhaust pipes as well as fabricating an extension to headers allow the factory megaphones to "upsweep".

Any suggestions?

the cross over pipes were fitted to the "specials" whilst the roadster models had none. this was due to the specials having shorter mufflers, the connecting pipe effectively "doubling" the exhaust length.

Drewpy,

Thanks for the reply, but what does that actually mean in terms of modification? Do you see any real problem with the following: We definitely have the crossover pipes on on our exhaust. I was thinking of simply cutting off the crossover pipe on both sides and welding it up, cutting the megaphones off the header and welding in an extension to the headers at an angle to affect an upsweep of the megaphone and weld the megaphone back on. It seems like a lot of work but even if I spring for the 2 into 1 I'll have to modify it to get the upsweep we're looking for.

We're working on a budget here and doing all the work ourselves but we'll do what has to be done to have a safe reliable rider.

Again, thanks for any help anyone might be able to provide.

sounds ok to me, go for it.

I think I'll give it a whirl. I was worried a bit about creating increased backpressure some how by blocking off the cross pipe.

This thread: http://www.xs400.com/forum/showthread.php?t=6313 showed a bit of the internals of the muffler but not enough detail so I'm rock sure there won't be a problem.

Worst that can happen is it doesn't work and I buy a 2 into 1 ( or a 2 into 2) new exhaust, or maybe even a used 2 into 2 off of ebay if I can get one cheap enough.

jmd...

Before you just "cut off" the mufflers from the headers, let me take a picture of my headers that i cut the mufflers off of from my 81s. It will help you alot to see where you are going. A large tubing cutter will be of great help to you. I will get the pictures posted later tonight.

oldgeek

Thank you very much for the help (from one oldgeek to another).

I hope the pictures help you out some. I put a white paint mark on the spot where i took a large pipe cutter, and cut off the muffler. Be careful to just cut the outer muffler. The headers are actually double wall pipe. They just stick into the muffler about 10", which is then welded on. You can see the weld just to the RIGHT of the white paint mark. 1 1/2" to the LEFT of the paint mark is the weld where the outer wall of the pipe is attached to the inner header pipe. You might be able to cut around the muffler LEFT of where i made my cut, and just extend the muffler part without messing with the actual header pipe. Good luck, and make sure to show us what you come up with.

oldgeek,

Thanks again for the pictures and info. I'm going to need to think this out a bit more before cutting or I'm likely to wind up with a bunch of scrap metal. I'm planning to start a build thread for our bike that will include pictures and more details.