How to Make a Scooter Exhaust Quieter

As your muffler ages, your scooter will sound louder.

As your scooter ages, holes can develop in the muffler, causing the exhaust to be released in more than one place and making the engine sound louder. This louder sound could also be caused by the air filter on the exhaust's intake or from damaged or old muffler packing, called a baffle. You can replace your scooter's muffler and air filter easily in about an hour; or if you can remove the baffle from the muffler, you can replace it instead of the entire muffler. You can also replace your current muffler with an absorption muffler that pushes the exhaust through a larger chamber, reducing its noise.

Things You'll Need

• Scooter
• New muffler
• New muffler gaskets
• New air filter
• Socket set
• Phillips head screwdrivers
• Lubricant
• Shop rags
• Pipe expander
• Anti-seize
• New baffle

Instructions

Removing the Old Muffler

1. Position your scooter on its center stand. Remove the screws holding the heat shield on the side of the muffler, below the seat, with a Phillips head screwdriver. Your scooter may also have a head cap, though if your new muffler comes with one attached, you do not have to remove this. The heat shield should have three screws holding it to the muffler, though this may vary by brand of scooter.

2. Use a ratchet to remove the bolts holding the muffler to the scooter. Check below the muffler to make sure you have removed all the bolts. At this point the muffler should only be attached to the engine by the head pipe. Some mufflers can be removed from this pipe though most will be welded to it.

3. Spray lubricant on the joint between the muffler and the head pipe and twist it as you pull it off the head pipe. If the muffler you are installing is attached to a new head pipe, do not remove the muffler; skip to Step 4.

4. Remove the four bolts or screws holding the head pipe to the exhaust port of the scooter's engine.

5. Pull the head pipe off the engine and remove the gasket.

6. Check the engine exhaust port for any buildup or debris that needs to be removed.

7. Install the new gasket and attach the new head pipe, making sure it aligns properly with the exhaust port. Attach the new muffler to the head pipe, if not already attached, securing everything snugly but not too tight.

8. Verify that everything is aligned and fitted properly, then tighten the screws and bolts. Check all the connections before reattaching the heat shield.

9. Start your scooter while it's still on the center stand and check the exhaust, holding your hand near, but not touching, the head pipe's connection with the exhaust port to feel if any exhaust is being pushed out the connections. If that is the case, you may need to detach all the parts and work on realigning the connections.

Replacing the Baffle

1. Position your scooter on its center stand. Remove the heat shield with a screwdriver then remove the bolts holding the muffler to the scooter.

2. Remove the muffler from the head pipe, loosening it with Liquid Wrench and twisting from side to side as you pull it backwards.

3. Remove the screws holding the head cap to the muffler and take off the head cap. This will give you access to the baffle.

4. Reach into the muffler and try to pull out the baffle. If it will not come out easily, spray it with anti-seize, let it sit for 30 minutes then attempt to pull it out again. If it still won't budge, insert a pipe expander and turn it until it sits snugly against the baffle.

5. Pull on the pipe expander to remove the baffle.

6. Slide the new baffle into the exhaust and make sure it fits snugly. You can insert the pipe expander to turn it to make sure the baffle is expanded properly in the muffler.

7. Reattach the head cap, then slide the muffler onto the head pipe and bolt it onto the scooter, making sure all the connections fit snugly. Reattach the heat shield.

8. Start the scooter, while it is still on the center stand, to test the sound of the muffler.

Replacing the Air Filter

1. Position your scooter on its center stand. Locate the air filter on the opposite side of the muffler.

2. Remove the screw in the center of the air filter case located directly under the seat. Remove the air filter case cover and set it aside.

3. Grasp the air filter and gently pull it straight towards you. Check the air filter case for any debris or damage. Clean it if necessary.

4. Push the new air filter into the case then replace the air filter cover.

Tips & Warnings

• If the muffler you have comes off of the head pipe, but the muffler you purchased is permanently attached to the head pipe, don't bother pulling the muffler off the head pipe, unless the muffler gets in your way when removing the head pipe.

• Not all mufflers will have a removable baffle. If your muffler is welded together, you cannot remove the baffle and will have to replace the entire muffler.

• Be careful not to scratch up any paint near the parts you are removing as you pull them off. It is best to use rags or old towels to cover painted areas near the parts you are working with.

References

• "The Complete Idiot's Guide to Motor Scooters"; Bev Brinson and Bryce Ludwig; 2007
• Motorcycle Touring Association: Honda ACE Motorcycle Page -- Drilling Holes in Your Baffle
• NSX Prime: Exhaust Theory
• Motorcycle Cruiser: How to Install an Exhaust Pipe on Your Motorcycle
• Vix Diagrams: Modifying or Replacing the Exhaust System
• Gadget's Fixit Page: Motorcycle Quickies

Resources

• "Yamaha Vino Owner's Manual"; Yamaha Motor Corporation; 2008