POS Yosh...

[The Buddha]

The stoopid pipe is so pock marked...I had a hard time sanding it and painting it and never could get it looking smooth and uniform. The stock header are much better quality IMHO. They always ended up smooth and easy to sand even when they were rusted worse.
Cool.
Srinath.

[Black Snowman]

I noticed that on mine. I painted it in Rustolium high-temp silver which has a flat finish and it makes it look like cast aluminium. Work with the flaws

[Rashad]

Hmm ... thats odd. My Vance and hines system has been sitting in some garage for the last 3 years. It was ALWAYS rusted... ever since i first saw the bike. So when i sanded the rust off and it was nice, smooth and shiny underneath... i was surprised.. but you would think the 'better' quality Yosh pipe would be, well, better.

[cruisedaddy]

As a bike technical nerd of sorts, let me just humbly opine that the OE headers are a great design and well fabbed.  I don't see any possibility for improvement without going to larger header pipes and that may hurt your bottom end.    I do believe that a freer flowing exhaust will help at higher rpms though.  So just the can, and not the whole pipe, I think, oughta be replaced.  The Yosh is a much higher quality unit than the Cobra (which is just a can -- you chop off your muffler and slip it on) or the V&H (which is the whole setup) but I got a deal on a Cobra and clearly it is flowing a tad better as I hooked up an EGT sensor to fine tune everything.  Way more important, the Cobra's sound is absolutely killer, too ... it's amazing that this little twin can sound so fierce with such a cheapo add-on.

[JamesG]

That Yosh has probably had a hard life.  That is the drawback to both the Yosh and V&H  the headers rust out fast because both used the cheapest mild steel tube for their GS pipes.

The Yosh pipe is better than the stock system rust and all. It is lighter by about 3 lbs. and greatly helps out the top end.  But it is a race system. It has higher maintenance and has to be removed to change oil filters.

[The Buddha]

The stock header pipes with an aftermarket can is just the same weight as the yosh. The cheapo pipe part I agree with. I also believe the Yosh is a thicker wall pipe than stock or V&H. It may have something to do with the pock marked look. However its on the bike and the odd looking spots are hardly visible.
Cool.
Srinath.

[JamesG]

The Yosh header pipes are a much thinner guage than stock and are "tighter" than OEM.  
New, the headers are as smooth as any other header. I think yours is just "seasoned" and allowed the rust to get a better hold than usual.

IMHO For a street bike, a stock header with a AM can is probably better. But for race bikes a straight thru 2 : 1 system is better.