mkimber

I installed my K&N today and the bike is acting funny now. It doesn't seem to rev smooth at all and sometimes it will stuter when I'm cruising around 4k. It will make a sound in the airbox that sounds like a backfire almost. Also, if I punch it, it seems to hesitate around 3-4k rpms.

I thought I installed the rubber caps on correctly. I just placed them in the right spot and pressed the filter on top of them. Do I need to do anything else? This seems kinda stupid but also too easy to screw up. I haven't had time to take it back off and look at it. The filter is brand new. Any help would be great. I plan to ride it to work tomorrow so I'll let you know how it runs.

Matt

Dave Wicks

As I have read on this site from the more knowledgable and experienced guys it sounds like the K&N install has a huge impact on the tuning/jetting of the Hawk. It sounds like changing the air-filter has more impact on jetting than the pipes. I'm sure there is help waiting. If I were you I would list carefully what you have for pipes and what has been done to carb's...ie what jets, idle mixture setting etc...It sounds like you have gone quite lean. Is your air box stock except for K&N?? Unless you are prepared and or able to rejet you can always put the stock filter back in until you are ready to do that...Hawkrider is the man on this stuff...Come on guys step in and help this guy.

Take Care
Dave

Hawkrider

Dave, you flatter me. BTW, IT WILL GET YOU KNOWWHERE!

Yeah Matt, what Dave said is correct. You're looking at a rejet if you stick with the K&N. The VTR is much more sensitive to intake changes than exhaust changes. I suggest you post the information Dave mentioned along with your elevation and order a jet kit. Either Factory or Dynojet will work, as folks here have had success with both. Dynojet requires a little more time and drilling holes in your carb slides. Factory is a little easier to tune and I can give you a good baseline to start with on that. Either way it's up to you based on price and/or availability. Once you get ahold of one post up and somebody will give you a good starting point. Plan on at least tearing into the carbs 2-3 times to get it tweaked correctly.

mkimber

Thanks guys. I have Jardine RT1 high mounts for exhaust. I live in Dallas so the elevation is 1500ish. I do already have a Dynojet kit but it's not installed. I assume the bike has stock jetting. I am planning on doing a rejet but not for a week or so. I will be taking the filter out tonight when I get home. I did notice the bike was running a lot hotter this morning also. At least it's easy to swap back.

superbling

Read the instructions for the dyno-jet kit. That should provide lots of answers.

gboezio

I hated the instructions, they have definitely been written by someone that is in the know, for someone that never disassembled a CV carb, it took me a while to figure out that the treaded end of the needle holder was a puller to be used with a cover bolt and to pull hard enough on this poor thing to slip the O-ring out of the grooves, but past that it was pretty straightfoward.

mkimber

You guys were definatly right. I took out the filter the other night and all is back to normal. I just need to find time now to install the jet kit. Thanks.

Dave Wicks

Some further K&N thoughts. I bought my wife a sweet little Ninja 250. It has a Muzzy 2 into one, Dyno jet kit and you guessed it a K&N. I got it late last year..never even rode it really. Got it warmed up the other night. In it's mid-range 5-8 thou. rpms...it was breaking up unless I started to pull choke on...Hmmm going lean in mid-range. Two choices.. trash the K&N or check needles setting. Raised needles two notches..starts better, less choke.. healthy in the mid-range...No road test yet, but it is better. I'm guessing a stock airfilter would have had similar effect. It has been jetted.. top end is fine..when you do your re-jet.. do some research on needle setting.

Take Care
Dave

Hawkrider

Yes, the K&N will affect the upper-mid and upper rpm ranges. Think about it. A paper filter flows just fine at low flows but will restrict more and more as the flow gets higher. So your largest change will be on the main jet, then you have to tune for the needles, which could be up, down, or the same depending on needle shape and how much larger the mains are now.

bluedog66

This may be bad logic but... People say that at this altitude my jardines cause the bike to run rich. So, since people say the k&n makes bikes run on the lean side, if I dropped in a k&n wouldn't I in effect even it all out? I am not too in the know with how carburation works so this is kind of just me thinking out loud...

Hawkrider

Yes, and no. Exhaust and intake mods affect the bike completly differently than elevation change. To some extent the mods affect low rpm performance but mostly it changes high rpm performance compared to stock. Elevation change affects the entire range, and I'm taking a guess here, but probably more low end than high.