Stock XS360/400 exhaust dimensions

[BBS360]

up.

Too bad the PO let the baffles rust out of the aftermarket mufflers. There's probably no back-pressure right now at all.

The aftermarkets aren't designed to have the baffles removed but I think I can cut them out and have something welded back in.

The mufflers do outwardly resemble the stock setup so I was wondering if it'd make sense to build the baffles close to stock dimensions and maybe get away without rejetting.
At least to match the stock inner diameter of the final exit port to keep the overall restriction close to stock.

Does anyone know the inner diameter of the exhaust port(s?) on a stock xs360/sohc 400?

I really just don't want to make things worse.

 

[xschris]

All the xs400 stock pipes I have are around 1" outlets. The 360 may be different. I don't think you could ever replicate the guts of a stock pipe as they are more than just a plate welded in there. I would look for a stock set or a good aftermarket.

 

[BBS360]

I did find the thread with the cut-open '81mufflers. Quite a few chambers and pipes in there. Too much to replicate.

These do have some inner chambers. Nowhere near stock I'm sure, but if I'm repairing the baffle and exit port I figure it shouldn't hurt to get the setup closer to stock.

There are currently five holes in the back of these mufflers. If the stock exit port is a 1" diameter these probably double the port area.

I may upgrade mufflers in the future as money allows but for now I'll have to get this setup workable.

Thanks Chris