The Yamaha PW50 has remained relatively unchanged for decades. One problem the PW50 has always had is the baffle in the exhaust blocks up with carbon and the bike won’t rev correctly. If your exhaust has blocked up or you just want to prevent this from happening then here is a trick for you for derestricting a PW50.

#1 GRAB PHILLIP

Start by removing the Phillips Head screw in the bottom of the exhaust that holds the baffle in place. These can be tight and require a good quality screw driver to remove.

#2 TWISTING TIME

With the screw removed, it is now time to remove the baffle. Most of the time the baffles are too tight to remove by hand so you will need to grab it with a pair of mutli-grip pliers and work it back and forth until it becomes loose and then pull it out.

#3 REMOVE A BIT

Now hold the baffle in a vice and use a hacksaw to saw off the torpedo looking end of the baffle this is the end that builds up with carbon and blocks up. The more of the baffle you cut off the louder the bike will become so I choose to only cut the torpedo end off and still leave a large portion of the baffle in place.

#4 DE-BURR THE CUT

With the torpedo end of the baffle cut off, Use a Dremel or die grinder to clean up any burrs around the cut area.

#5 REFIT TIME

Now clean up the baffle and refit it back into the exhaust system. Twist it back and forth until you line up the thread in the baffle with the bolt hole in the silencer.

#6  SCREW IT TIGHT

Place a small drop of Loctite on the lock screw and then tighten it back into place.

FURTHER PROBLEMS

If you have performed this modification and the exhaust still seems blocked and the bike still won’t rev correctly then remove the exhaust from the cylinder and check inside both the cylinder and exhaust for carbon build up. It is common for carbon to build up in this area as well and block the exhaust. The carbon in this area can pack in so hard you will need a die grinder to remove it.

DO’S

  • Only cut the tip of the torpedo off of the baffle.
  • Clean up the baffle before refitting.
  • Put Loctite on the retaining bolt.

DON’TS

  • Loose the spring washer on the retaining bolt.
  • Cut too much of the baffle off or it will become too loud and lose back pressure and performance.
  • Squash or distort the baffle in the vice or it will not fit back into the exhaust.

TOOLS:

Vice, hacksaw, screw driver, multi grip pliers, rags, Loctite.

WARNING:

This modification will make the exhaust louder and is not recommended if you want the bike to be quiet as possible.