Modifying Stock Intruder Pipes

This simple modification will reap great benifits in the areas of power, throttle response, and miles per gallon. It will also create a nice deep growl from your Intruder, about two - three times as loud as stock at idle, but much louder when you open up the throttle. But the sound is not nearly as loud as drag pipes, so your neighbors will still love you and your friends will still ride with you.

I found my Intruder to be much quicker, without a hint of throttle lag, after modifying my pipes. As an added bonus, I also increased MPG, getting 45 - 48.5 in mixed city and open road driving, and documenting a very real 53 miles per gallon for an all day, two-tank average for the two-lane mountain roads in North Georgia.

Step 1:

Take a 1/2-inch drill bit on an electric drill (the cordless won't cut it here) and drill three holes in the outer baffle of the exhaust pipes. This will be rather difficult, as the outer baffle is actually two steel plates back-to-back, not just one. Once you get through the outer baffle, keep drilling until you also get through the middle baffle, about 5 inches further down the pipe. Space the holes equally between the retension rivits, as shown below:

WARNING! DO NOT DRILL TOO CLOSE TO THE CENTER HOLE! If you do, you will hit the inner structure and not be able to drill the inner baffles. If you drill to match the drawing below, you will not have any problems.

Step 2:

Take a 1/2-inch "installer's" or 'jobber-length' drill bit (available from Home Depot for about $12) and drill through the center hole of the factory baffles. Drill throught the outer, middle, and the inner baffle, located about a foot down the pipe towards the engine. See below:

That's it! You're done, except for using a touch of flat-black, high-temp paint to paint the outer baffle to make the holes less visable. You will not need to change the jets or adjust the carbs at all, as Intruders, unlike most bikes, to not run lean after you open up the exhaust a bit. Low and mid-range torque will be up, so this modification alone should make you very happy. The idle is deeper and louder, and at open-throttle the bike will roar nicely, but not obnoxiously.

Run the bike for a bit, and drive it for a couple days. If you REALLY want more noise, go ahead and drill three * 3/8-inch holes in the inner baffle. This will make the bike really loud, and probably create a little bit of a throttle lag. Drilling out the last baffle will cause an Intruder to run too rich, so your exhaust may smell like gas and your MPG will suffer. The MPG will not come back, but you can eliminate the gas smell by leaning out the carbs a bit or re-jetting.