Drill the Stock Exhaust (stage 1, 2, 3)

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Stage 2

Introduction

Stage 2, as this is generally referred to, is the process of drilling “blindly” into the lower baffle plate.  This is accomplished using a long drill bit and drilling through the holes that you drilled in the first baffle plate and into the second baffle plate.  The effect is a slightly louder exhaust.

Again, it is recommended that you remove the mufflers from the head pipe, and take them off the bike.

1. Using an 18” long drill bit, enter the holes that you drilled for Stage 1.  Find the second baffle plate and drill random holes in the plate.

*Note... The effect that stage 2 has is minimal.  Generally speaking, if Stage 1 has grown old, or if it does not provide the desired sound, you should skip Stage 2 and go to the Stage 3 modification.

Stage 3

Introduction

The Stage 3 modification seems to be the most popular.  In fact I have done 3 sets of Stage 3 pipes without ever stopping at Stage 1 or 2.  The process essentially defeats the 1st and 2nd baffle chambers and uses only reduction and re-direction as the means of baffling the sound.  The modification is reasonably simple and once Stage 1 is complete, you’re half way there!

1. Using a 1” hole saw, drill out the first baffle plate in an overlapping fashion, essentially eliminating the baffle plate entirely.  You will leave jagged edges, and a center pipe that is no longer supported.
2. Using a hammer and chisel (or comparable tool) push the jagged edges that are attached to the center pipe back out of the way.
3. Using the same method, push the jagged edges back that are around the outside edge (attached to the inside wall of the exhaust) of the muffler.  You can also grind or cut them off, although this is time consuming and the net effect is the same.
4. Insert something sturdy into the center pipe.  Whatever it is, it should fit inside the pipe tightly, and give you a firm area to grip.  You will then twist and turn the center pipe, using as much force as possible, until you feel the weld in the bottom of the pipe give way.  Continue working the pipe until it comes completely out of the muffler.
5. All that is left is to clean up the inside of the pipe by working with the leftover edges and using some flat black spray paint.

It is strongly recommended that you re-jet the carburetor at Stage 3.  A Dyno-Jet kit using a 165 to 170 main should be sufficient.  You do not want to run too lean and because the stock setup tends to run lean already, allowing exhaust to exit easier tends to exaggerate the condition.

The end result will be a better running, better sounding bike, no matter which stage you choose.