Ok, I just did this due to swedish regulations on having the swedish equivalent to the DMV, to inspect my wifes bike. This is done every 2 years here in Sweden. This have certainly been done by many other members of this board, but I couldn't find any threads here on it, when searching.
With my shortys on the XS400 it's way to loud for swedish regulations. Not even with the short after market mufflers mounted inside them I'm not even close to pass a decibel test.
This is what I did. Bare in mind that this can't be used all the time, since the heat build up in the exhaust may ruin your exhaust valves.
This is what you'll need:
A can (or two) of your favourite beer. (This is if you have an exhaust leak between your exhaust pipe and muffler).
Some pliers.
A pair of scissors.
Dish washer metal balls? Tried to translate that from swedish - didn't work at all. That's the metal steel wool looking balls in the picture. I used a total of 8, just to be sure.
Some wrenches.
Maybe some zip ties - depending on how much beer you drink prior to attempting this.
A sound level meter (if you have one, otherwise go by ear - that's good enough).
1. Remove the mufflers inside your shortys.
2. Remove your shortys. (If you have no leaks between your exhaust pipes and your shortys, skip to point 6)
3. Cut up an empty beer can using your scissors. Make sure the cuts are clean and even or they will be a PITA to fit.
4. Wrap this cut up beer can around your exhaust pipe where your shorty fit.
5. Slide your shorty back on. This part is the trickiest one. To do this without tearing your beer can wrap. You might need a zip tie to hold your wrap in place and "screw" on your shorty. Or even better use that big pair of pliers. Should look like this if done correctly:
6. Now stuff those metal washer balls thingys up in your shortys. I used 4 per exhaust. Feel free to use more or less, but know this, more means more heat build up in your exhaust.
7. Put your mufflers back in your shortys. If you don't run after market mufflers, drill out 4 holes about 1,5 - 2 inches from the end of your shorty. Put 2 bolts through and lock 'em up with nuts, so they make a cross inside your exhaust. This will stop you from shooting those balls out when you fire it up.
8. Time to check the sound level meter. I put the bike at about 3000 rpm (I think) as when inspected here in Sweden. 88,2 dB - well within the limits wich is 102 dB here in Sweden.
9. Now I had to get these metal washer thingys out, since I don't want 'em in for the whole ride to the inspection. Pull your bolts or after market mufflers. Start it up and give it one good rip on the throttle. Now go fetch those washer balls.. Put your mufflers back in your shortys, put your metal washing balls in your pocket and bring your wrenches as well.
10. You might wanna do this half a mile or so away from the inspection site, but I did this in their parking lot. I pulled my mufflers, using the wrenches I brought and stuffed in my metal washing balls. Passed the inspection. Removed the washing balls in that very same parking lot - and rode home.
Now I don't have to do this for another 2 years..
Feel free to add or comment on this How To. It worked for me and may work for others. On a side note, it was so quiet that they didn't even check the decibel..
With my shortys on the XS400 it's way to loud for swedish regulations. Not even with the short after market mufflers mounted inside them I'm not even close to pass a decibel test.
This is what I did. Bare in mind that this can't be used all the time, since the heat build up in the exhaust may ruin your exhaust valves.
This is what you'll need:
A can (or two) of your favourite beer. (This is if you have an exhaust leak between your exhaust pipe and muffler).
Some pliers.
A pair of scissors.
Dish washer metal balls? Tried to translate that from swedish - didn't work at all. That's the metal steel wool looking balls in the picture. I used a total of 8, just to be sure.
Some wrenches.
Maybe some zip ties - depending on how much beer you drink prior to attempting this.
A sound level meter (if you have one, otherwise go by ear - that's good enough).
1. Remove the mufflers inside your shortys.
2. Remove your shortys. (If you have no leaks between your exhaust pipes and your shortys, skip to point 6)
3. Cut up an empty beer can using your scissors. Make sure the cuts are clean and even or they will be a PITA to fit.
4. Wrap this cut up beer can around your exhaust pipe where your shorty fit.
5. Slide your shorty back on. This part is the trickiest one. To do this without tearing your beer can wrap. You might need a zip tie to hold your wrap in place and "screw" on your shorty. Or even better use that big pair of pliers. Should look like this if done correctly:
6. Now stuff those metal washer balls thingys up in your shortys. I used 4 per exhaust. Feel free to use more or less, but know this, more means more heat build up in your exhaust.
7. Put your mufflers back in your shortys. If you don't run after market mufflers, drill out 4 holes about 1,5 - 2 inches from the end of your shorty. Put 2 bolts through and lock 'em up with nuts, so they make a cross inside your exhaust. This will stop you from shooting those balls out when you fire it up.
8. Time to check the sound level meter. I put the bike at about 3000 rpm (I think) as when inspected here in Sweden. 88,2 dB - well within the limits wich is 102 dB here in Sweden.
9. Now I had to get these metal washer thingys out, since I don't want 'em in for the whole ride to the inspection. Pull your bolts or after market mufflers. Start it up and give it one good rip on the throttle. Now go fetch those washer balls.. Put your mufflers back in your shortys, put your metal washing balls in your pocket and bring your wrenches as well.
10. You might wanna do this half a mile or so away from the inspection site, but I did this in their parking lot. I pulled my mufflers, using the wrenches I brought and stuffed in my metal washing balls. Passed the inspection. Removed the washing balls in that very same parking lot - and rode home.
Now I don't have to do this for another 2 years..
Feel free to add or comment on this How To. It worked for me and may work for others. On a side note, it was so quiet that they didn't even check the decibel..
