Do I need to rejet for this exaust?

[Anonymous]

I resently bought a 2000 GS500E. And because I live in Boston I need a louder exhaust (it's not safe other wise). I got a Cobra F1s. Do I need to rejet for this exhaust?

Alittle background on me. I have been riding for about 3 years. My first bike was a 1985 GS700ES. God, I loved that bike. I bought it for $1.00. It had been sitting in a garage for about 10 years, not winterized or even had the gas drain out of it. It took me some time (and some money) to get it running. I learned a lot about motorcycles from that bike. I could always fix cars, I have had a series of crappy cars, so I had to fix them myself. In the past I use this wedsite quite a bit, when I fixed the carbs for instance. For that this site was invaluable. Unfortunately, I crashed that bike. Thankfuly I dressed for the fall and not for the ride. So after taking a slider at 50, I walked away. Anyway thats my story, abriged. I hope that some of you can help me. And if any of you are in Boston, look me up, I'll drink a beer with you.

Thanks,
Todd

[KEITH KRAUSE]

I'm not familiar with that exhaust. I would ask the maker if possible.
Regardless of what they say however, I would still test the bike and get plug reads at lower cruising speeds and then 3/4 to open throttle if you can. Do what the plugs say.
If the pipe does flow better than stock, then you may have to go up a full size on your main jet and probably an additional 1/4 to 1/2 turn out on your mixture screws?

[Pete's GS]

I would expect to have to re-jet since, even stock, this bike was notoriously lean. You may want to see the gstwin.com website and its jet-kit evaluation and advice.

[Billy Ricks]

Maybe not. The F1 is just a slip on if it is the same as it was years ago. You're still using the stock header and connectors if so. As long as you don't get any pinging or popping you should be okay. Do plug readings to be sure. As someone already pointed out, most bikes are jetted lean to get past EPA regs.