Gnarly FMF Exhaust Pipe

[gymrat86]

Hey guys I am looking to buy a brand new Gnarly FMF Exhaust Pipe. I am new to dirt bikes but just purchased a 2003 kawasaki KDX 200. When I install this on my bike will I have to do any thing special or just bolt it on and im done. Also do I need a new spark arestor with it also. One other thing, what is a good and easy way to lower the bike? I am on my tippy toes when on this bike. Im 5'5 - 5'6 and weigh 145. I tried softing the spring but im afraid to softing it all the way cause I dont want to bottom out. Thanks for your help
-Paul

 

[the trail rider]

as to the pipe you will have to rejet but nothing else sorry i cant be more of use on info.

 

[KDXruss]

Do a search on lowering and you will find plenty of info!

 

[Jackpiner57]

Please do yourself and all of us a favor: Please leave your STOCK silencer on. The Gnarly will still give you a very noticeable increase in power. It will help to keep offroad areas open to us dirtbikers. Even the MX tracks are starting to require quieter bikes, because they are in danger of being shut down.

 

[Jackpiner57]

Also, click on my name and do a search of my other posts. There will be one titled "Do I Need a Louder More Powerful Pipe?" It is an excellent article I found on the Blue Ribbon Coalition website. Read the whole thing and also the replies to the post. You will find a wealth of info there. You will find that quiet is important! Also, you will read replies that say that louder is not more power. This is very true. Happy QUIET riding! :aj:

Please read this:



QUIET PLEASE! -- TWO BIKERS TELL A TALE OF SOUND
by Charlie Williams & Bill Uhl



--------------------------------------------------------------------------------


I was up on a hill the other day and ran into a friend of mine, Billy Uhl, a leader in our sport of dirt biking. Billy was the top American finisher at the 1973 ISDT, as well as a 9-year vet at 6-Days' competitions.

These days, Billy lives in a quiet mountain setting from which he does trail construction and maintenance. Billy has watched our sport from behind the scenes for many years, so if we are smart, we will listen when he speaks.

When I ran into Billy, I was out riding for fun and looking for new subjects to write about. Billy had a subject for me - noise and sound. He works on the trails up here in Idaho. He'll ride his old bike up a hill, park it, then cut and dig trails all day long. Billy loves his "office." He had heard me coming, and I have a quiet bike. It's a 250 two-stroke with a good silencer, so it's never revved up on the pipe. It's stealthily quiet, yet he had heard me for the last couple of minutes.

As we talked, I mumbled along about this and that, only to have him turn his head to say "Huh?" Billy can't hear well out of his left ear. He blames it on years of chain saw and bike use without earplugs.

Here is a guy who loves dirt bikes and riding, deaf in one ear, but he still noticed the sound of my reasonably quiet bike. At one point in our visit, he perked up like Radar on M*A*S*H, saying "Jet plane. You can hear them for two and a half minutes."

"I never paid any attention."

"Exactly," replied Billy. "You can hear a plane for two and a half minutes, but people are used to them and don't pay any attention. So they block them out, just like you've done."

I perked up with my new-found sound sensitivity. "Dirt bike, four-stroke."

As the rider came closer to our side of the small valley, I looked at Billy with surprise. The bike we had been listening to was now within a couple of minutes of us, but it appeared to have given birth to two other bikes that we could now hear softly purring. The entire journey across the valley had taken about ten minutes, but we only heard one bike until the last two minutes.

"This is exactly the point," Billy clarified. "Our sound is normally not audible as far away or as long as that of the jet plane. Because traditionally, motorcyclists stay in the acceptable range of sound, they're only audible for a short time. In this case, we heard one bike a long way off for a long time, and the other two bikes only a short time."

Three happy trail riders had now rolled up, one with a big-man exhaust. Billy tactfully told the loud rider that we could hear his bike from the time he crested the ridge on the other side of the valley. The guy just shook his head while saying something about the bike needing to breathe, so he had opened up the silencer.

Now, I was puzzled and made a caustic comment. "Why do they call it a silencer if it makes more noise?"

The guy explained that he needed the louder exhaust to get the most power out of the 450, and my sarcasm again rode to the surface. So I asked, "Are you a famous racer?"

"Well no."

"Are you in a big race right now?"

"No," he replied sheepishly.

"Then why do you need to disturb everyone for a quarter of a mile around just so you can trail ride?"

"Because I like the power." He was getting defensive now, but I was filled with questions.

"Can you actually use the power? Couldn't Larry Roseler beat you on an 80cc bike? Haven't you noticed that one of your buddies was in front of you?"

Our conversation soon ended. Billy strapped his chain saw back on his dilapidated Kawasaki. I strapped on my helmet, and the five of us took off. The booming four-stroke was right behind me, or so it seemed because the noise was right on my shoulder. I made some good turns, and soon it felt like I must be getting away from him though it sounded like he was still on my fender.

The five of us rode a few miles before Billy stopped to clear a fallen tree. I rolled up, removed my helmet and started to help. Then the loud bike showed up. We had made our point. It's not the bike or the power; it's the rider.

Bob had been transformed. "I get your point, fellas. I'll put the quiet stock exhaust back on my bike. If a guy in hiking boots riding a tool wagon can outride me, then maybe I don't need the little bit of extra power a noisy exhaust might give me."

His friends were beaming smiles. We all laughed, then Bob and his companions rode off. Billy and I listened to Bob's loud bike for quite a while. He was being light on the throttle now, trying to slip away without making any more noise than he had to.

We sat on a log, overlooking the mountains of Idaho. You could see for hundreds of miles in all directions. Huge pine trees and rocky crags towered above us. Streams cut their way through valley floors. Birds chirped and chipmunks skittered about. Mountain lions and wolves live there too, not to mention elk and deer and all the other friendly woodland creatures. A 24-inch wide motorcycle trail snaked its way along, following old miners' routes that had followed the traces of Indians who had followed animal trails.

You get the picture? There is a tiny ribbon of trail zigzagging around. Everyone is happy until someone puts a loud bike on it. Suddenly, noise can be heard for about a quarter of a mile to the north and south -- a half-mile-wide corridor of unnecessary noise is created just so one loud biker can use 24 inches of trail! (Note: Sound travels different distances as terrain changes. We are using the worst case scenario - a ridge trail.)

Billy said, "They keep coming after us. Sound will be the next issue."

"They who?" I jerked around and looked over my shoulder looking for bears, wolves, or mountain lions.

"The government is coming. When they outlawed two-cycle engines, they thought that would close us out or at least make it more difficult. So factories started building better four-stroke motors, and our sport struggles on."

"Yeah, and the sound a four-stroke makes carries a lot differently than a two stroke." I said trying to stay in the conversation.

"Yes, the four-stroke's sound carries differently. But anymore, the snowmobile guys are running straight expansion chambers and can be heard from a mile away. That's a two-mile corridor of noise. I love snowmobiling and ride them all the time, but it's annoying to listen to them all day while I'm at home."

"They have three cylinders - that's 140 to 160 HP! How much more power do they think they need?"

"They don't need more power. It's just like the bikes. It's not the power - it's the rider and the ability to ride well. To the public, any sound that is different from what they are used to is "bad." One loud bike can turn them sour against all riders. It's the same with loud snow machines. Somehow we have to rally the troops and police ourselves."

"If we don't do it, the government will, and I guarantee that we won't like what they do to us. We need to convince the manufactures to stop selling loud exhaust systems. Nobody needs the noise or the hearing loss that emerges from it. We have to get them to sell us good, quiet systems. People just don't realize that trails and tracks are being closed to us because of what's called 'sound pollution.'"

"You know the Speedway guys have gone to quiet exhaust, and they have a new track right in town. Back in Indianapolis, Speedway participants share the parking lot with an exotic dance club, so how much noise are they making?" I asked.

"Hearing loss, land closure, fatigue; these are just a few problems with noise. Sound could be the next battlefield. Did you know they are using money from the Green Sticker program to buy decibel meters? How stupid are we? Are we really going to finance our own demise? If we don't address the sound issue on our own, we will be committing recreational suicide."

I answered, "You know, I went to a desert race the other day. They started in three rows, A, B, and C. The A row was pretty quiet. Most of the four strokes had stock exhaust, and the two cycles didn't stand out as loud. The B row had a couple of loud bikes, but the C row was the noisiest of all three! Most four-strokes had big man exhausts on them, so what we are up against is educating the beginners."

I continued, pretty much rewording what I had just said. It sounded good last time; let's see if I can pass it off as genuine thoughts again. "The expert riders understand that loud exhaust is not good. They know it fatigues them, and the manufacturers understand noise is not good. Manufacturers just build them because the educationally unencumbered buy them, thinking they need the noise. The public hates the sound, and other riders are also annoyed by it. Nobody craves hearing loss, and none of us want more land closures."

Billy continued. "Even on 'closed courses' noise is a problem, if the MX track is bothering neighbors a quarter of a mile away, the government has no other choice but to shut the track down."

"Yeah, they claim the loud pipes are just for closed courses, but they sell them to anyone. The buyers then use them everywhere, not just on closed courses. Just a few moments of noise can sour our potential supporters."

"A closed course?" said Billy. "If the sound travels like it does here in the mountains, then that makes the closed course with a quarter mile radius of angry neighbors. These neighbors don't care whether it is closed course or trail riding. All they know is bikes create sound. They don't like it, and they are going to act against us. Neighbors are going to call the cops; the cops call a meeting; the public gets organized; they come after us, and I don't blame them one bit. We have a responsibility to clean up our act."

I went on, "You know, we had the noise issue going pretty good once the two cycles became water cooled and good repackable silencers became practical. It's only been in the last few years, when the so-called racing four-stroke came back on the scene that noise became an issue again. Most of the four strokes are quiet from the factory. It's the after-market people who are feeding this problem. How do we convince them to stop selling the loud ones and focus on building good quiet ones? If they only would, the problem would solve itself in time. All the loud bikes would soon become outdated and pushed to the barn."

Billy continued, "I'm afraid the ignorant will always want more noise. They relate noise to speed, which is so wrong. To really ride well, you need to be one with the bike. You need to feel the RPM; you need to feel the ground through the tires and the pegs. If the bike is deafening you, how can you feel these things?"

Billy went on, "Even if we get the major manufactures to quit making loud pipes, ignorant companies will start building loud pipes. We need to make sure everyone knows just how uncool it is to be noisy. Michael Lafferty's 450 racer is quiet, so why does Joe Schmoe think more sound means more power. If Michael doesn't need it, why does the C class?"

Billy's passion for riding and the trails was so evident. "We've really got to make everyone conscious of this problem because it is threatening all of our rights to ride. We need to change, and we need to change now. If we don't, the government will continue to force change, and we all hate that."

As I gathered my things to leave, I told Billy I would write a story for the magazine. Most of the readers I know are already on the quiet bus, so it's the uninformed that we must reach. We have to counteract the propaganda that more noise means more power. You are of a higher plane of consciousness, and we need your assistance in educating those who are unconsciously creating offensive noise levels.

We need to start by enforcing noise restrictions at all of our races, events, and outings. Enduro guys do a good job, but the Hare Scrambles, MX, and family crowds could do better. The clubs need to change their rules and stand by them. Riders want to ride, so they will follow the rules and buy quiet exhausts.

Manufactures want to sell. If we as riders and clubs demand quiet pipes, they will produce them so they can sell them. We can go after the licensing organizations like the AMA, FIM, etc., and make them change their sound rules. The noise issue is finally one where we can start at the bottom and work our way up. If riders demand quiet, everyone above us will fall in line.

When I got back to the trailer home, I did a little research on hearing loss. It turns out the ear canal is filled with tiny hairs that change the mechanical energy of incoming sound waves into nerve messages to the brain. Sustained noise like a bike or a chain saw damages these tiny hairs, causing permanent hearing loss. Ear plugs are not always the cure, because some sounds travel right through the skull and cause damage. There is not enough research, but I'd bet a noisy four-stroke bores right through the skull. It does mine.

When I shared this article with Billy, he made one last comment. Apparently, "Einstein once said, 'Insanity is doing the same thing over and over again and expecting a different result.' Sound does not have to become loud, annoying noise." Billy has a passionate plea, "Noise has to change to a sound level that is acceptable, so go forth and ride quietly."

My advice is to do something now! Write the manufactures, the after-market people and the race organizations to demand quiet pipes. Contact the clubs and demand quiet races, repack your own silencer, and educate your friends and family. Lead by example because our future depends on our making a difference. Like Billy said, if we wait for the government to do it for us, we will not like what they do.

--ﾩ 2004 Charlie Williams & Bill Uhl. For comments or questions on this article, the authors may be reached through the BlueRibbon Coalition: 4555 Burley Drive, Suite A, Pocatello, ID 83202. Phone: 208-237-1008, Fax: 208 237-9424. Bill Uhl, Senior Instructor, OHV Training(TM), may be contacted directly via email at: <[email protected]>.

 

[JST122]

gymrat86, it is very easy to change the exhaust on a two stroke, especially the KDX 200. I own a 97 KDX 200 and I swapped the stock pipe for a FMF gnarly as well, and I swapped the stock silencer for a FMF turbine core II spark arrestor. The benefit to this combination is increase horsepower and response without added noise. The turbine core II spark arrestor is EPA and US Forrestry Service approved for sound and back fire spark protection. The gnarly pipe would be louder than the stock pipe with a regular silencer but if you couple it with the stock silencer/spark arrestor or the turbine core II you will maintain the stock noise level in decibles and maintain the spark arrestor qualities. What Jackpiner57 is saying is very true and likewise important so if you do swap out silencers with this pipe make sure you do it with the EPA approved turbine core II or something similar that is approved by the EPA and U.S. Forrestry Service.

As far as changing the pipe goes all you need to do is remove the frame bolts and the exhaust springs (an exhaust spring puller makes this easy they cost from 5-10 bucks) needle nose pliers will work as well but are definitely more difficult and you risk loosing grip and having the spring snap back. Once the springs and the bolts are off you can just pull the pipe off. To put the new pipe on you should first loosen the bolts on the stock spark arrestor (if you plan to leave that on) this will allow you to adjust both the pipe and spark arrestor to ensure a solid, leak free joint between the two pipes. Replace the rubber o-rings that are on the end of the stock pipe if they are worn and put them on the new pipe. Sometimes new 0-rings will come on the new pipe you order, if not FMF makes replacement exhaust springs and o-ring kits for pretty cheap. Once you have replaced the O-rings, you should put a Thin Layer of high temp silicone gasket sealer around the end of the pipe that will go into the engine's exhaust port, as well as on the connection point between the spark arrestor and main pipe. This will provide a tighter seal and ensure you dont have leaks. (You can pick up high temp silicon gasket sealer at most autoparts stores, they even sell motorcycle specific brands, one is called motoseal.) Next insert the pipe into the engines exhaust port and if the stock spark arrestor is still on connect those two pipes, hold it into the exhaust port firmly and put the exhaust springs back on the pipe. This will essentially hold it in place while you put the frame bolts on. Next put in the frame bolts and just snug them up enough so that the pipe is held up and in place and then do your final adjustments to the connection of the spark arrestor and main pipe. Once everything is lined up correctly begin snugging down all the bolts evenly. Start it up and check for any leaks, you should be good to go.

 

[Rhodester]

On the silicone thing....my O-ring(s) that go on the pipe seal just fine. I've done multiple pipe changes, adding/subtracting torque rings, etc., and I've never had a exhaust leak at the cylinder flange. Even with just 1 o-ring in contact (as with the T-ring) it has never leaked.

 

[Jackpiner57]

I am of the opinion that nothing is as quiet as the stock silencer. Therefore, I will not run anything but the stock silencer. I also don't care what the accepted decibal limits are for USFS. It's the people that are annoyed by the noise that I'm worried about. They are the ones complaining and changing the laws and closing down riding areas. They are the ones that are trying to prevent Jeremy McGrath from riding his motorcycles on his own property! I go for quieter than USFS limits. Make noise and kill our sport. Period.

 

[kmccune]

I am of the opinion that nothing is as quiet as the stock silencer. Therefore, I will not run anything but the stock silencer. I also don't care what the accepted decibal limits are for USFS. It's the people that are annoyed by the noise that I'm worried about. They are the ones complaining and changing the laws and closing down riding areas. They are the ones that are trying to prevent Jeremy McGrath from riding his motorcycles on his own property! I go for quieter than USFS limits. Make noise and kill our sport. Period.

:nod:

 

[ridejunky]

My son was riding his fully stock Husky 50 on our private property and we got a complaint from someone whose lawn mower is much louder and his straight piped chopper is off the decibal charts. You can barely hear the husky run. Some people just hate dirt bikes, go figure!

 

[GS]

People that hate "something" or anything for that matter are MOTIVATED to look for an opportunity to shut it down. I always "good neighbour" folks I meet on the trail. Go very very slow or stop while they pass. If you like riding...you better try real hard to see that they leave with a good impression of both your manners and consideration for others
...Jus' my 2 cents...

 

[JasonRan]

We were riding at 143 Off Road this weekend in Tennessee and there were these guys on 4 wheelers with the loudest exhaust you have ever heard. You had to cover your ears when they went by! I determined that they were just all around idiots because they would do like 40mph through the parking lot and the speed limit was 5mph. Kids everywhere! I hate when people like that think that just because it is loud, THEY are fast. I have found this to be the exact opposite. It's like they have to have a loud bike/4 wheeler to make up for their lack of riding ability. I am very much a beginner rider, but I still keep my bike quiet. Don't want to draw attention as I fall in the parking lot. :)

 

[Red_Chili]

Agreed, Jackpiner...
I am the Land Use Coordinator with our Toyota 4x4 club, work with the local USFS districts to maintain roads and trails, and am a big fan of multiple use trails. There are really two things that will kill OHV sports:
1) Noise.
2) Not Staying on the Trail.

On average, motorcycles are big offenders on these two, ATVs are worse (particularly # 2). 4x4s are NOT innocent either. What it comes down to is interfering with others' enjoyment of public lands. Nobody likes noise in the woods, and nobody likes mud bogs and user created trails in the woods.

I know the ultragreen groups are shrieking about 'user conflict' and some even set us up for it (by blocking trails and baiting conflict, no kiddin'), and I would love to say it's all a cynical conspiracy, but it's not, not always.

So whatever mods we do, we gotta be good neighbors. Plus I get to save $$$ on that dadgum silencer!!!

Back to silencers though, anyone run the newer 'Q' version of the Turbine Core II? Supposed to be uberstealth. Does it work? Is it quieter than stock?

 

[Rhodester]

Red Chili, I run an FMF 'Q' (bought in '04). I haven't run my bike with the stock silencer so I can't make a comparison. However, it is way quieter than the Turbine Core (1) silencer that I used to run. It's also somewhat quieter than the TC 2. The noise coming out of the sides of the engine and pipe is louder than the sound coming out of the end of the silencer. I can't tell any difference in the power output between the TC (1) and the 'Q' either. I'm very happy that I went with the 'Q'.

 

[Sunny State KDX]

I'm all for quiet bikes but lets not get carried away. I race in the FTR Hare Scramble series in Flordia. This is the first year we have got serious on sound due to riding areas being closed (thank you Thundering four strokes). I have an FMF gnarly pipe and Tubine Core II silencer. We have started to test bikes this year at the HS races. They haven't made it mandatory yet but by the 06/07 season 95db will be the MAX. we have seen many 250 and 450 four strokes with full race MX systems putting out well over 99db some as high as 102. They have been warned and told to comply. By next year you will be given a warning at the first race and if you haven't corrected or at least made an attempt to get closer to 95db by the second event your packing up and going home. My bike put out a whooping 89db's. :ahhh: Even with a TC II silencer the pipe makes way more noise than the silencer allows out.

 

[cr 85 6]

if your going to get a pipe stick with fmf but have a look at the SST pipe ive tried different pipes but the one that works best for me is the fmf sst .The gnarly wich gives you power gains from bottom to mid range power, the sst gives you power gains bottom,mid,and top.

 

[Red_Chili]

Red Chili, I run an FMF 'Q' (bought in '04). I haven't run my bike with the stock silencer so I can't make a comparison. However, it is way quieter than the Turbine Core (1) silencer that I used to run. It's also somewhat quieter than the TC 2. The noise coming out of the sides of the engine and pipe is louder than the sound coming out of the end of the silencer. I can't tell any difference in the power output between the TC (1) and the 'Q' either. I'm very happy that I went with the 'Q'.

Good to know. I'd love info on side-by-side comparo with the stocker. If it's even quieter, I'd buy it for the stealth assets.