Header OD dimension

[Lefty]

Can anyone tell me the outer diameter of the stock header pipe? I'm looking to (at the very least) replace the stock muffler & probably the header.

[J6G1Z]

Hey there Lefty,

I had my muffler off a while back & measured the collector outlet O.D. Unfortunately I can no longer recall what the measurement was. Some help that was, eh?

I ordered a one piece reverse megaphone muffler offered by EMGO off of a seller on eBay. It came with 3 collars that are used as a shim to allow the muffler to fit several different sizes. Mine fit just fine, but it is a bit on the too loud side. EMGO has since released a nice black 2-piece reverse megaphone that you can take apart & re-pack the silencing core to make it more quiet.
Here is one: http://www.ebay.com/itm/Matte-Black-Shorty-Cafe-Muffler-Reverse-Cone-Cafe-Racer-Bobber-Exhaust-Custom-/201073572087?pt=Motorcycles_Parts_Accessories&hash=item2ed0eb38f7&vxp=mtr#ht_101wt_916
There are several eBay sellers that offer the EMGO products, so it pays to shop around. The example that I listed wants far too excessive shipping, so I would search for a more reasonable seller. Here is the EMGO Exhaust Catalog PDF: http://www.emgo.com/images/pdf/2013_Muffler.pdf
Check out Page #3 for some reverse megaphones. I like the Model #80-84030B.

Some guys have adapted a Sport-Bike cannistor type of filter, but you have to be careful that the cannistor isn't too large looking. For example: http://www.ebay.com/itm/UNIVERSAL-DIRT-BIKE-STREET-MOTORCYCLE-BLK-RACING-EXHAUST-SLIP-ON-MUFFLER-NEW-/131075250940?pt=Motorcycles_Parts_Accessories&hash=item1e84b19afc&vxp=mtr#ht_3764wt_1153

There is also the Super Trapp type of muffler. Try to find one of their universal fit mufflers. This gives you the ability to adjust the amount of noise & how well the exhaust flows by adding or subtracting the silencer disks. For example:
http://www.ebay.com/itm/SuperTrapp-3in-Disc-Clamp-On-Silencer-1-1-2in-38mm-Black-317-1500-3M1500-/331169516446?pt=Motorcycles_Parts_Accessories&hash=item4d1b3dcb9e&vxp=mtr#ht_1786wt_867

I will see if I can't get you a measurement by the end of the day. I can at least get the muffler inlet I.D. for you.

Good luck
J.

[Lefty]

Thanks for the info J6G1Z, I'm most definitely going with the Supertrapp, I'm hoping to get the newer style, with the flat end, or the (I think it's called) the RDS model, which has the discs, but the outlet is more like the one in the 2nd link.
  From reading your posts, it looks like I'm going to have to fab up a hanger for it. I'm excited to get the performance level increased & do the 520 conversion,but it'll take time as I work crazy hors & have other obligations.
  Thanks again for your help, Brian.

[J6G1Z]

Well I didn't have any luck in measuring the stock exhaust O.D. & I seem to have misplaced the original muffler.

The after-market performance header by ThumperStuff has an O.D. of 1.747", 44.4mm, or just about a 1 & 3/4" across with the tape measure.

Good luck
J.

[Lefty]

Thanks for that info J6, I found my extra caliper & measured the header- I got what you got, right around 1 3/4"

[scottly]

I measured a stock pipe a few weeks ago, so I could make an adapter for an old canister-style muffler I had in my stash of parts. Just got it test fit on the bike today! I'll try to take some pics...
The OD of the pipe itself is about 1.66", but the OD of the sleeve gasket, and the ID of the stock muffler is 1.87".
Hope this helps.

[scottly]

Pics of my "new" muffler. Note the gnarly new rear tire.

[J6G1Z]

Looks good! What is the muffler from & how is the sound?

What's with the rear tire? You been Hill Climbing lately?

J.

[Lefty]

Real cool! I love chunky tires on street bikes, I'm cosidering tire choices for mine( too bad I have brand new OE types right now), but that's a way down the road.
 Great looking pipe too- I'm also interested in to hear what it sounds like....

[scottly]

The muffler is an aftermarket "Muzzy", that had been fitted to a portable arc-welder I bought over 20 years ago. At low loads, it has a pleasant thump, but it is a bit loud at WFO, which it has seen a few times recently on the dyno.

[J6G1Z]

Is it a "straight through" design like a glass pack? They tend to boom at full throttle conditions. Have to release that energy somehow. Usually all that noise is behind you anyway. 

J.

[Lefty]

After searching for a couple weeks, I've decided to go with the SuperTrapp that you posted a link to in this thread. The Ebay pipe listed says the inlet is 1 1/2". Is this going to work with my ThumperStuff header(yes, I made the deal on the phone with Mark Saturday!), seems like it may be too small?
 I checked my bank acct today for the charge for the header & he has not billed me for the header & jets yet. I'm going to call him tomorrow.

[J6G1Z]

1.5" Would be too small.

You need to have a muffler inlet I.D. in excess of 1.75"

Good luck
J.

[Lefty]

 I've changed my mind & am looking at this SuperTrapp pipe, it's 18" long with a 1 3/4 inlet. I'm anxiously awaiting my ThumperStuff header to see what kind of adapter I'm going to have to fab/buy to make this pipe more horiziontal, so I won't lose the passenger peg.

[Lefty]

Ooops, it's the one in the back....

[J6G1Z]

I believe the angle of the Header exit allows the pipe to be angled upward & still clear the foot-peg just fine. You will need to fabricate a strap from the passenger peg to the muffler to support the muffler properly.

J.