Air box delete with Honda intakes - TUNED

I built up a '83 Honda CB650 Nighthawk for a customer a few months ago and deleted the air box/exhaust on his bike for the build. I jetted the bike and shimmed the needles and it ran perfect. The intake tubes that are on a stock Nighthawk are the perfect design for even smooth airflow without using the entire box housing. They pull out of the stock air box for a nice 4" length. They are a one-in-two flow design.
So I bought a set off ebay and found out they are too big for the XJ carbs. I machined up some adapter rings out of delrin to make them work. Then I cut the "snout" part off the intake tubes to have a flat surface for filter material. I then machined up a filter plate to hold the filter material to the tubes with two 6-32 screws.



I tuned the carbs by installing 41 idle jets and 120 mains with the needles shimmed .028" and the pilot screws richened a 1/2 turn. I runs perfect. Maybe a touch on the lean side. I want to try some 125 mains or larger. I also have no exhaust. I have a vid of it idling/revving. In the vid I have the filter ziptied to the intakes for testing.

http://youtu.be/c7eZAjUC9mw

 

Did you do a plug chop for your test? What material are you using for the filter?

 

yes, plug chop showed a bit lean. Had some white ash on the electrode, insulator has no color on it. For filter material I doubled up some filter mesh used for house AC filters.