Pipes...

[RadMax]

Thanks again guys! Say, what jets are you running? Typically - I know it’s a pretty hearty four-stroke, but for what it’s worth, I live in Pittsburgh, and like to ride at least nine months out of the year.

 

[RadMax]

Not to slag off the previous owner, but when I got my bike it had that rotted 2-into-1 turnout, a stock airbox, and aftermarket jets (I forget what - I only have one set and they’re in the carbs right now - but they’re bigger)... And it’s never really “sounded right”, if you know what I mean? (I’m assuming just about everyone here has bought a used bike at some point in their life, XS or otherwise.) I put Emgo cone filters on it, but other than that they’re just rebuilt and jetted BS34s.

I’m SO GLAD to finally get rid of this 2-into-1, if anything I swear it’s hurting my performance.

 

[5twins]

I'm assuming your EMGO cone filters are the pleated K&N style? If so, that type of pod filter doesn't work very well on these CV carbs and can cause tuning issues. Best pod choice for these is the UNI straight foam type. For your BS34s, that would be the UP4229 or UP4229ST (dual layer) .....

Honestly, you don't really need the dual layer ones pictured above. I only have them because I got them cheap from a local guy because they wouldn't fit his bobber. And don't use the special foam filter oil they sell for them, it's too thick and can clog them. Instead, just oil them with a simple 50-50 mix of motor oil and gas. I bought a bottle of cheap Walmart straight 30 wt. specifically for this .....

For jetting, go up 2 on the mains (from 132.5 stock to 137.5), one on the pilots (from 42.5 stock to 45), and one down on the air jets (from 135 stock to 132.5). Set the mix screws about 2.5 turns out.

 

[TX650A Van Islander]

Further to 5twins comments about the bolt inserted into the baffle plate, I have those pipes as well and after 5twins told me about it back in 2020, I bought some appropriate bolts and inserted them, using lock washers. Taking off the pipes, pointing the opening down, and screwing in the bolt vertically was the best way to do it without dropping the bolt inside the muffler. The sound difference is slight for sure, but I left them in. Before and after videos are attached. Note that unfortunately this was not a controlled sound test as the distance from the bike to the phone recording the video was not the same, wind noise was not the same, and the videos were taken almost a year apart.

Before:

After:

 

[nj1639]

^
Yours purrs more on throttle with them in than mine does without.
I'll keep mine out for now, 'specially since the inserts are on vacation somewhere......
Thanks for the vid.

 

[Kevin Werner]

A twin runs best with a 2 into 2 exhaust using long, tapered megaphone type mufflers. BMW discovered this when they had an endurance race team back in the late '70s. Stock headpipes are very restrictive. Even though they look pretty big on the outside, the "pipe-in-pipe" design makes the I.D. quite small. The aftermarket 1.5" headpipes they sell are pretty much perfect, bigger, but not too big. Too big is no good either, they rob low end and midrange power, only making good power in the high RPMs new redline. If you've ridden an XS650 for any amount of time, you know running up near redline just isn't done much. This bike's "forte" is low end and midrange "grunt". For mufflers, the original type Commandos with the removable baffle bolt are about the best out there at the moment. You can get them with 1.5" inlets so they fit on without reducers. They can be found at YamahaXS650.com. Don't buy them from Mike's, they're not the "real McCoy", they're EMGO copies and are literally shit.

Do these pipes mount using the passenger peg loop off the frame? I am contemplating shorty reverse cone mufflers but I am not certain how they might be supported.

 

[5twins]

Yes, they hang off the rear-most mount on that loop, where the passenger peg mounts. My original '78 pipe hanger bracket was too far forward .....

..... so I swapped on some XS500 brackets .....

Even with those, the muffler didn't quite mate up, but it was close enough. The forward bolt is just outside of the sliding track on the muffler but it effectively "clamps" the bracket to the track .....

 

[Kevin Werner]

Tossing this out... shorty 17 mufflers welded to head pipes and a strap bolted to muffler mount and clamped to rear down tube. Would that be enough support?

 

[nj1639]

Twins has the upswept headers iirc.
I've got straight 1 1//2" od pipes, Standard bracket was nowhere close to mount these 27+/-" muffs. I installed a set of Special rear foot pegs with a hanger off that threaded stud. Ground a flat on the upper end of the hanger to facilitate the foot peg staying in situ. Having a foot peg in hand clarifies the need for that flat........

 

[grizld1]

No need to weld the muffs to the head pipes. Attach the head pipes to OE pipe mounts with P clamps and hang brackets off the passenger peg studs to support the mufflers. It's too late and too cold to take pics now, but I'll post a couple in the morning.

 

[Kevin Werner]

No need to weld the muffs to the head pipes. Attach the head pipes to OE pipe mounts with P clamps and hang brackets off the passenger peg studs to support the mufflers. It's too late and too cold to take pics now, but I'll post a couple in the morning.

Passenger pegs and passenger peg frame loops are gone.

 

[5twins]

Yes, I don't know why folks do that, cosmetic reasons I guess. The few ounces of weight savings certainly don't amount to much.

 

[grizld1]

Sorry to see that. I guess pics won't help at all.

 

[Kevin Werner]

One option might be replacing the foot peg casting with an aluminium plate mounted on the frame bosses that mounts pegs forward with an extended ear back to mount a muff support.

 

[BowlingSS]

Sportster mufflers are quality, quiet, and flow well, often available in brand new condition for pocket change.

I put a set of Harley mufflers on my old XS1100. They were quiet. Got them both from eBay for cheap.

 

[Kevin Werner]

I was considering how I would oil my new Uni pods. Post 43 covers it. Thanks @5twins.

 

[Kevin Werner]

No need to weld the muffs to the head pipes. Attach the head pipes to OE pipe mounts with P clamps and hang brackets off the passenger peg studs to support the mufflers. It's too late and too cold to take pics now, but I'll post a couple in the morning.

I am not seeing shorty reverse cone mufflers with a 1 1/2 inlet and it was mentioned that reducers always leak. My thought was to mount and align them, tack weld in place and then remove the exhaust system and weld the whole joint.

 

[grizld1]

Reducers always leak? Guess I was just lucky. I ran 1-1/2" and 1-5/8" pipes with shorty megs and reducers for years and never had a problem. You just have to careful about how you align the gaps and cranks down hard on a heavy duty T-clamp; hose clamps won't cut it. (BTW I'm using 1-3/4" pipes only because that's all I could find in stainless.)

 

[arcticXS]

Reducers always leak? Guess I was just lucky. I ran 1-1/2" and 1-5/8" pipes with shorty megs and reducers for years and never had a problem. You just have to careful about how you align the gaps and cranks down hard on a heavy duty T-clamp; hose clamps won't cut it. (BTW I'm using 1-3/4" pipes only because that's all I could find in stainless.)

I got a pair of 40 mm OD stainless pipes from Heiden Tuning in 2021. Most likely exactly the same as these:
https://www.xs-laden.de/shop/navi.php?a=340&lang=eng
They are fairly thick wall, so ID is similar to thin wall 38 mm/ 1 1/2" tubing. These pipes look like a close replica of stock headpipes, maybe the "early" type. They are a bit shorter than the common aftermarket 1 1/2" chrome pipes, and have no "kickup" at the muffler end either. So in my case, I'll end up welding a short piece of 38 mm on to them, as my mufflers require that. If there was/is any suitable 40 mm mufflers, they may work without any added tubing (adapter).