K&N without rejetting???
 

I've got an '03 Hawk with Jardine RT-1's and I need to replace my stock airfilter... If I get a non-stock air filter (K&N, BMC...) will I need to rejet the carbs? I've noticed that most people who have an aftermarket exhaust and airfilter also have rejeted the carbs. Any one who has had sucess without rejetting?

My understanding is that jetting is suggested for exhaust mods and required for aftermarket filters. So you would have to rejet if that is true. But my bike is stock so I have no personal experience in this.

I have 2 Bros exhaust and a K&N filter and it ran horrible til I jetted it. There is just too much air flow for the carbs to keep up.

Rejet?
 

I just had this same conversation w/my Honda service tech. He said to install the Jardines and go ride and see if everything runs OK. Normally, slip-ons are just that. Slip-on and go! However, the air box is a whole different animal. A switch to a K&N/BMC filter will definitley need to be rejetted and in his words not mine, you may actually get little if any improvement. And then he reminded me that there are a whole bunch of highly-paid engineers sitting in Japan designing this stuff to work just right.

K&N = lots of work + no gain

sounds like a good idea to me. a search will yield a lot of experience on this exercise

It's a good idea to do if you're going to rejet anyway. You still have to go through the tuning process, right? With that said, you're looking at another 1-2hp, maybe three from the filter. Between pipes, filter, jetting, and maybe an advancer you should get about 8-10 hp more, depending on how well you (or your shop) tunes it.

Thank you all for your input. This has confirmed my suspisions-that if I try a K&N I'll likely have to rejet. I was going through the 24k maint and need to replace the airfilter anyway, wasn't sure I wanted to cough up $50+ for a stock airfilter when a K&N is a little less than twice that...I really don't want to rejet and retune yet and the bike really does run well as it is-not to mention that it sounds great too. Thank you all!

I am running a k&n with only the carb needle shim mod and the bike runs great... I still have the stock exhaust on it though...