I need the DL on these K&N filters

[Kygor1]

I wanted to install an aftermarket air filter. Whats the best? I only come across these K&Ns. I bought one from DennisKirk.com. But I am thinking about returning. I only hear bad things now that I purchased it . Why are they so bad for the Katana???

[gobigorange189]

yep, get your money back asap.

[Kygor1]

yep, get your money back asap.

Oh I will ASAP! Are they just not reliable or something? Any other brands to look for?

[gobigorange189]

keep the stock air filter in there... there will be MANY people on here that will tell you its the best...the K&N's are pretty much impossible to get tuned correctly. when i first got my kat, i didnt believe all the K&N bad talk, so i got one anyways...and yeah i quickly took it out and agreed that stock was much better..

[Kygor1]

Alright, thank you for the heads up. I will make note of that.

[Cheriff]

I think the "why" is because they let too much air into the airbox which messes up with the airflow in the Kats CV carbs.

[arsenic]

I think the "why" is because they let too much air into the airbox which messes up with the airflow in the Kats CV carbs.

something like that. A K&N, UNI, pretty much any after market air filter is what's known as a "hi-flow" air filter. The Katana has CV or constant velocity carbs. They rely heavily on vacuum pressure. With a "hi-flow" air filter it is flowing more air in, thus vacuum pressure is not the same. Due to the Katana's mild cam lobe height and over lay, the Katana does not require a "hi-flow" air filter. The collector portion of the exhaust header can not even fully collect all the air from the oem filter. So why would you want to add more air. In order to jet the CV carbs for a h-flow filter, you would need to allow WAY more fuel to match the WAY more air. You'd be running super rich. You would still have flat spots in the RPM range due to not having the correct vacuum pressure. That's it in a nut shell.

[Kygor1]

Awesome response! Thank you!

[arsenic]

I do that sometimes most of the time I'll just call you a ****tard

[JokerZwild]

I do that sometimes most of the time I'll just call you a ****tard

musta got his new perscription of Paxil in!

[arsenic]

I'm just starting to realize that this accident, that made me take a total 180. That most people would probably consider the unluckiest thing possible. Was really the luckiest thing that ever happened to me. I have way better credit now, I have a brighter future then I did before. I would have been perfectly happy in my crappy life, with a total ***** wife. Now I got possibly the best girl ever. I should have married her when we were together at the end of high school, but I guess I had to go through all of this to find out who I am.

[landofsong]

Maybe there should be some sort of STICKY about what not to do with your Katana and then attach some sort of link as to why not, such as the in explanation Arsenic put together for K&N air filters.

[Cheriff]

It wouldn't matter. No offense to OP at all, but this question would still be asked daily.

[70sdiscotrike]

Good thing to know - this was going to be one of the first items I bought for my Kat.