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I need new exhausts. What should I get? Print E-mail

Last updated: Tuesday, 26-Feb-2002 12:18:32 MST

Exhaust Systems FAQ

written by Doug Heinen
edited by JP Honeywell

This FAQ on exhausts for the XS/XJ11 attempts to answer most of the questions that come up often on this website.

Some questions that commonly come up are:

My pipes are rusting. Can I paint them?

Sure you can! The finish may be not the finest, and you may have to do it again but a good high-temp paint can do the job. Some people buy paint from the auto store, some from the motorcycle shop. Yet others have used Barbecue (or VHT) paint - usually with mixed results. Sources have told me that the high-temp paint (used on the jugs) sold by the Harley dealer is among the best around, but you can be sure it's not the cheapest.

Why do pipes rust inside out?

Pipes rust from the inside out when moisture in the air condenses inside the mufflers and pipes when it cools down after a ride. (especially if the bike is only taken for a short ride and parked over a dirt floor or the ground or lawn outside!)

My pipes are bluing. Why does it happen and how do I remove it?

Pipes turn blue because of the heat being generated in the engine. This usually is an indication of the carbs running slightly lean and the engine runs hotter than normal. This happens more frequently on some brands of replacement pipes that have thinner (read cheaper) chrome plate and/or thinner walls {on the} as well. The bluing may be prevented with a generous coating of high-temp on the INSIDE of the pipes prior to be being installed for the first time. If you don't paint it before you use the pipes - even once - don't bother. It needs to be done on "virgin" pipes only. There are some preparations that can be applied on the outside of the pipes after installation, but will not keep it from happening again.

I want the most "performance." (whatever that means :-\ ) What should I get?

The most POWER gains come from exhaust systems that offer the best exhaust scavenging from the engine combined with larger jets being installed in the carbs to increase the amount of fuel being taken into the engine. Most notable are the Kerker or Supertrapp systems listed below. You might also want to look into the Thermo-Tec exhaust wrap described below.

How do I maintain my stock pipes?

The best maintenance is cleanliness. Wash the dirt and grime that collect on the pipes. They will attract moisture to the outside of the pipes and the moisture will cause any pits in the chrome to rust. Clean them with a soft plastic brush and a grease releasing dish soap like Dawn or Ajax dish soap (Not the abrasive cleanser). Steel wool, Brillo pads, and green scrubby pads will scratch the soft chrome and ruin the finish. If your pipes are starting to become rusty or are pitting then the cancer has begun. At this point, you can only slow down the inevitable. A good non-abrasive polish, such as Mothers creme (available at any m/c shop and most large discount stores, Kmart, Walmart, etc.), will clean off much of the discoloration caused by a small amount of rust. You'll be surprised how much better your chrome will look after just these two steps. But you'll still have to protect your newly cleaned pipes (and other chrome). Then wax the dickens out of them. Always try to park in a covered area (this does not mean under sap producing trees!) and over plastic to prevent the moisture from the ground from collecting on or in the mufflers. I know we don't all have this luxury, but even a lean-to on the side of the house made of Visqueen plastic and 2"x2"'s will do the trick!

How do I refinish my Midnight Special pipes?

This is a tough one because the coating on the Midnight's pipes is a ceramic, not truly a chrome finish. The best I've found is a company called Jet-Hot Coatings. They coat both in the outside AND the inside of the pipes/mufflers with a black ceramic that is not quite as shiny as the OEM finish but is much harder and longer lasting. Yes, it is shiny, but as much as original. Jet-Hot can be reached on the web at http://www.jet-hot.com or call them at (800) 432-3379. They can coat the exhaust in several different colors and they claim it even boosts performance because the coating on the inside of the pipes is smoother than stock and allows the gases out faster. (Faster is good!)

Do I have to replace the header pipe crush gaskets every time I remove them?

It's always a good idea to do this, but I've been told by people who have to remove their headers every oil change that they have re-used them and not had any exhaust leaks. Best advise is to replace them if you can, but if they're not too badly mashed, you might be able to re-use them. If you have to remove your headers often, check with your napa store to see if they have the right size. It will probably be cheaper and more available than Yamaha. {you can't, try not replacing once and see if they leak.}

Why do I have to change jets with some new pipes and not others?

Easy one: To increase performance and keep the engine running cooler. Some pipes, by their design, do not increase the exhaust flow out of the engine over the stock exhaust system. So you do not need to re-jet. When the exhaust gases escape faster they make the engine run leaner. This increases the heat in the engine. There may be some performance gain over stock merely due to the better "breathing" efficiency of the engine. To get the most performance and best efficiency out your engine the carbs should have slightly larger jets installed to increase the amount of fuel taken into the engine. This increases horsepower and allows the engine to run cooler.

New Exhausts: What are my options?

The OEM Yamaha exhaust system: This is the most expensive system in the world! They are outrageously prohibitively expensive. Reports are over $1000US to $2000US. What do you get for this ransom? A perfect fit, ease of maintenance, good looks, reasonable noise levels. If this is in your budget and those are your goals, GREAT! Go for it! If not, read on.

After-market exhaust system: You have several choices in several price ranges here.

Jardine offers you a choice of 4-into-1 or 4-into-2 Priced from $280US to $360US in your choice of Black w/canister style muffler or Chrome megaphone style muffler. More affordable than OEM with good looks. Some versions DO NOT allow access to Oil Filter housing so the exhaust system MUST be taken off for routine oil-filter changes. Some versions require removal of center-stand, SO ASK! Some performance gain if carbs are jetted to match. NOTE: performance gain most notable with 4-1 systems due to exhaust scavenging. (I'm not going any deeper into the performance aspects as these are VERY individual.) Not always a perfect fit depending on the model. Better (?) sound: more growl, deeper tone.

Mac offers your choice of 4-into-1 or 4-into-2; from $234US in black to $241US in chrome. Your choice of Black Ceramic coated or Chrome. They are the least expensive after-market exhaust system. Good looks. Some versions DO NOT allow access to oil filter housing so the exhaust system MUST be taken off for routine oil-filter changes. Some versions require removal of center-stand, SO ASK! Some performance gain if carbs are jetted to match. NOTE: performance gain most notable with 4-1 systems due to exhaust scavenging. (I'm not going any deeper into the performance aspects as these are VERY individual.) Not always a perfect fit depending on the model. Better (?) sound: more growl, deeper tone.

Kerker offers 4-into-1 ONLY. This is one the systems that can substantially improve performance if the carbs are jetted properly. Requires removal of center stand (WHICH can be used in the garage for servicing but must be removed while riding - it hangs too low - only about 2 inches off the ground {while riding}.) Poor availability. Most expensive after-market system at $500US to $550US (depending on dealer) Choice of black (paint, not coating) or chrome megaphone style. Repackable muffler. Louder, but pleasant exhaust note (great in tunnels!) Poor access to oil filter.

Supertrapp is available in 4-into-1 ONLY. Substantial performance gain if carbs are jetted properly. Poor availability and more expensive than other after-market systems. Choice of black (painted finish, I believe) or chrome megaphone style muffler. Repackable muffler and louder, but pleasant exhaust note (great in tunnels!) Poor access to oil filter. Tuneable for performance or sound level by removing or adding "discs".

Replacement mufflers

If your header pipes are still in good shape then you can do this job with MUCH less expense and hassle! New mufflers can mounted to the existing original header pipes either as Slip-ons and Weld-ons. There are a wide variety of manufacturers: Jardine, Cobra, others distributed by JC Whitney so be sure to check with your local bike shop, parts house, or bike wrecker/parter. There are too many sources of these to be listed here so just do a little homework. If you are located in a remote location, then ask the group and we'll always give you loads of advise! Be aware that your header pipe diameter is 1.5" (STOCK) at the header and at the collector. The Slip-on style muffler utilizes a clamp to connect muffler to header pipe. Good price: from $75US to $250US per pair with decent looks, usually chrome ONLY and widest variety of choice of style. You can be very individualistic looking: baloney cut, taper cut, reverse taper, megaphone, flared megaphone, turn-outs, fishtails, shark-fin, etc. You should confirm the mounting bracket locations or be able to compromise and rig your mounting hardware. The weld-ons mounting bracket location is not as critical due to strength of the weld-joint to the header pipe and they will require pretty good welding skills or just have a muffler shop do it!

It is also possible to put Harley-Davidson mufflers or BMW mufflers on your XS Eleven. Check out this tip. I'm hoping for information on the BMW muffler to come forward soon.

Additional modifications
by JP Honeywell

Another interesting concept is ceramic header wraps. There is a company called Thermo-Tec which sells a 1 inch and 2 inch material that you wrap around the header pipes much the same way you would apply an ACE bandage.

This is according to the manufacturer (whom I spoke to): "When you wrap the pipe, the exhaust gases will maintain their temperature. The wrap will retain 70% of the heat that would normally radiate off the pipes. When that happens the gasses become less dense, they flow faster and produce exhaust scavenging. You'll get better power, better economy and more torque because of a richer fuel mixture. You may need to adjust your jets accordingly."

[I was under the impression that exhaust scavenging created a lean - not rich - condition. But I'm no expert. - Ed.]

Certainly it will prevent you legs from baking as a result of less heat from the exhausts. That alone make make it a worthwhile investment.

One racer suggests that they allow better cooling by keeping heat from being transferred back into the cylinder and head by airflow. That may be true since the air around the pipes will be much cooler with the wrap installed.

One problem, though, is that they don't look as nice as chrome or ceramic finishes such as on original Midnight Specials and Jet Hot refinishing. It'll probably look even worse after a few hundred miles of bugs & road grime. The benefit is that it's fairly inexpensive, adds power, economy and it makes for a (probably much) cooler ride on summer days.

This stuff costs less than $50 for 50 feet of 2" wrap - enough to wrap your header pipes. It's available through your local speed shop or direct from the factory.

P.O. Box 96
Greenwich, OH 44837
TEL: (800)274-8437
Insulating Exhaust Header Jacket Covers

Additional notes about Thermo-Tec
by JP Honeywell [May 11, 1998]

Last summer I decided to try the Thermo-Tec exhaust wrap. All in all, I'm a bit disappointed. The first disappointment came when I realized that the wrap and the stainless steel clamps must be purchased separately. The clamps are made up of two parts. A coil of flat stainless steel 'banding' which you cut to length and the slide on 'locking device.' The 'banding' looks, at first glance, to be the same stuff that metal hose clamps are made from - only not quite as wide. The 'locking device' is just a piece of stamped stainless steel which is supposed to secure the banding. The wrap also comes in one long piece, wound in a coil.

Now you must determine how long a piece of wrap you need for each pipe. I would recommend attempting to determine the length of one of the longer pipes first. There are guidelines in the instructions but your wrapping technique could require more or less wrap than the guidelines. By choosing one of the longer pipes first, if you cut your wrap too short, you might be able to use it on one of the shorter pipes.

The instructions call for you to dampen the wrap but not to soak it. I was not able to figure out how to do that since the stuff starts out acting slightly water repellent and then without warning seems to become a super-absorbant paper towel. Working the material is tricky at best and you might want to wear latex gloves. Practice definitely helps.

Since you are required to create your own clamps from these two parts, there's a bit more work demanded of you. First, you'll have to determine how long a piece of banding you'll need. Then you need to cut the piece of banding off of the 'coil.' I found that diagonal cutters will do an adequate job if you cut it at one of the holes in the banding. (This will make sense once you see the banding.) The problem is that this leaves some very sharp edges on the ends of the banding. This stuff will slice you like a knife if you're not careful - and sometimes when you are. You'll probably want to grind off the sharp corners and ends with a Dremel tool or a bench grinder if you don't care for lacerations.

Now comes the fun part. You get to make the clamps from the metal parts and tighten them into place. This is definitely a blood, sweat AND tears operation.

But the biggest shock and disappointment comes when you start the bike. (Of course you're doing this part outside. Nobody would run their bike inside the garage.) This stuff stinks when it gets wet. I told myself, "this will get better once it drys out." And it does get better once it drys out. The problem is that life on a bike is not always dry. Get caught in the rain - it stinks again. Take a ride after it rains and the wrap gets wet - it stinks again. Splash water from a puddle on the wrap - it stinks again. And of, course, it gets much worse when you have to stop for a light or for traffic. Because then you don't have the wind blowing the stink past you. You just sit there in the middle of the stink. Acheing to start moving again.


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