If a maker of a full motorcycle exhaust system says their exhaust is for off road use only such as racing. Would this mean the exhaust is very loud or just not tested and approved buy the DOT? I am referring to the newly made exhaust from Jardine that fits 2004-2007 gs500f.

Typically, If marked for Off road use only , means its a race pipe and isnt E marked

Quote from: 07gs500 on September 28, 2007, 12:58:28 PM
If a maker of a full motorcycle exhaust system says their exhaust is for off road use only such as racing. Would this mean the exhaust is very loud or just not tested and approved buy the DOT? I am referring to the newly made exhaust from Jardine that fits 2004-2007 gs500f.

It's not a direct "replacement" of the stock pipe as certified by the DOT.  This means you can get a fix-it ticket for "modifying" your stock exhaust system, if a cop were to care.

According to Jardine they state that this exhaust system will run around 100 dbs. Is that really loud? How loud is the stock exhaust? Also Jardine says: "With our exhaust system you should re-jet your bike". Is this really necessary?

Stock Gs's are Leanish from the Factory , so even stock a rejet is Recommended

130 db is a Aeroplane Taking off

The stock system is 90 @ 4600 rpm according to its exhaust sticker on my 05.

The jardine is louder, so could be considered illegal in some places. So jardine are just covering themselves so a ticketed rider can't say "BUT jardine said it was ok!"

Most aftermarket parts are classified as "for off road use only" for this reason.

I live in North East Ohio. There are currently no emission checks that I have ever been subjected to. I doubt it would be an issue. Most of the Harley riders have exhausts that are drag racing loud. I would assume I would not have an issue   Also for the bike to remain mechanically sound, if I installed the Jardine exhaust would I absolutely have to rejet my bike?

You could get away with leaving your jets as is with 'just' an exhaust if you really really don't want to rejet it. The bike will run a touch leaner at higher rpms.

I tested my jardine with the stock jetting and it ran ok. Just runs better if you re-jet it.