Motorcycle Repair: 2003 Honda Shadow VLX 600 - is rejetting necessary?, jetting, mufflers

Question
Hi, I have a 2003 Honda Shadow VLX 600 and I just ordered some Cobra Fatty Shotgun Exhaust pipes and I was wondering, will I have to rejet the carbs? -note, i have not changed the air cleaner or anything, everything else on the bike is completely stock minus the new pipes on the way- ...if I dont rejet the carbs, will it damage my engine? I've heard so many people say you need to, and so many people say you don't.. I just don't want to do anything to ruin my engine! any help would be much appreciated! thanks!

-Blake

Answer
Changing the way an engine breathes without changing the jetting usually won't do any harm to the engine. My own GoldWing has had Harley mufflers for 10 years with no adverse effects.

However, if you have access to the right test equipment, you can almost always achieve the best performance by matching the jets to any exhaust & intake modifications. The problem is that a lot of exhaust systems on themarket are designed primarily for looks and, no matter what you do, merely make the bike louder while actually producing less horsepower than the stock setup.

I strongly advise against making your bike significantly louder. Contrary to the popular saying, loud pipes don't save lives.  They just make your neighbours wish you would move somewhere else and not come back to visit!

I would expect that there is even an occasional death caused by someone with a loud exhaust startling a motorist and causing them to drive out of their lane.

With the soundproofing & stereos in most cars these days, other drivers really can't hear your exhaust noise until you are right beside them. Oncoming drivers (the ones that always say "I didn't see him") won't hear you no matter how loud they are - most of the sound is behind you.

Loud pipes also make it harder for you to hear sirens and other sounds that might warn you of danger.

On top of that, there are a growing number of people who would like to see bikes legislated off the road and loud pipes only provide them with more ammunition.

All that aside, I highly recommend joining a god discussion forum that caters to bikes like yours, such as http://www.hondashadow.net/index.php You may even find someone who has already done what you want to do and can tell you ahead of time what the results will be.