Modded air box

[themetalman03886]

I modded my air box after installed truck stacks, big idles good and runs good up to 3000 rpms then kind of chokes, like running lean. Should I rejet or what? Kind of regretting this air box mod.

[Garry 2r's]

I have a extra air box if you need it. I was going to do the same thing but after more research opted not to. Not sure about jetting mine has never been touched and runs excellent .

[Pete]

Try 'unmoding" the air box using duct tape. If that works buy a new or used air box.

[JaysGone]

I learned the hard way too.
No modding of the box works.
Get a "new" used one someplace.

http://stores.ebay.com/PinWall-Cycle-Parts-Inc/Valkyrie-/_i.html?_nkw=air+box&_fsub=3442307014&_sid=12458664

[Daniel Meyer]

The valk has an aggressive cam and a significant intake pulse. The airbox is designed to take advantage of that (it's called intake scavenging, and is similar in principle to the way header design uses pulses from one cylinder to help evacuate another). Honda does a very good job of this on the Valk and the newer Wings as well.

Translation: The airbox isn't just there to hold the air-filter. It is designed specifically and to a fine degree for our exact engine/cam/timing/rpm profile. I'm not sure it *could* be improved. 

[themetalman03886]

Garry, I sent you a PM...

[Chiefy]

What kind of Mod did you do to it?

[Blackduck]

There is no ifs or buts, you do any mod to the airbox including just removing the sound absorbing foam you have to re-jet.
Depending on what you have done will give you a start point for jet sizes.
Foam pad removal will take 102-105 mains, removing the baffle will get you up around 110 and after that you will just have to keep trying larger jets till you get it right.
Major surgery can have you up to 130 mains.
Believe I could nearly pull and replace the carbs with my eyes closed now, have had them of that many times.
Unless you have plenty of time, patience and a good selection of jets or jet drills go with the above advice and repair/replace the airbox.
Cheers Steve

[Valkpilot]

There is no ifs or buts, you do any mod to the airbox including just removing the sound absorbing foam you have to re-jet.
Depending on what you have done will give you a start point for jet sizes.
Foam pad removal will take 102-105 mains, removing the baffle will get you up around 110 and after that you will just have to keep trying larger jets till you get it right.
Major surgery can have you up to 130 mains.
Believe I could nearly pull and replace the carbs with my eyes closed now, have had them of that many times.
Unless you have plenty of time, patience and a good selection of jets or jet drills go with the above advice and repair/replace the airbox.
Cheers Steve

Just to avoid some confusion, I don't believe the U.S. model airboxes came with sound absorbing foam, or if they did, I've never seen one with it.

[Pete the Greek]

How are you running the "Truck stacks"? Over your OEM 's or with just the "Collector" in them or are thet Baffled?

I'm running 4" Harley straight pipes inside the stock exhaust with the collector for years now , runs great and semi quiet unless i crack the throttle then it barks loud! Have a K&N with washers raising up the front of the tank a little and a DynaJet kit on #3 with a 6 degree Trigger , love how it runs and gets great MPG same as stock , for some reason!

[9Ball]

There is no ifs or buts, you do any mod to the airbox including just removing the sound absorbing foam you have to re-jet.
Depending on what you have done will give you a start point for jet sizes.
Foam pad removal will take 102-105 mains, removing the baffle will get you up around 110 and after that you will just have to keep trying larger jets till you get it right.
Major surgery can have you up to 130 mains.
Believe I could nearly pull and replace the carbs with my eyes closed now, have had them of that many times.
Unless you have plenty of time, patience and a good selection of jets or jet drills go with the above advice and repair/replace the airbox.
Cheers Steve

Just to avoid some confusion, I don't believe the U.S. model airboxes came with sound absorbing foam, or if they did, I've never seen one with it.

That's true...the euro models also run smaller main jets....78s I believe.  Less fuel requires less air therefore the foam insert.