Air box mods

[chronyx]

Seen a few references on here to air box modifications.

Are they just for extra induction noise, or do they help with power/pickup?

Don't know much about this sort of thing...last time I read about air box mods was back in the days of my 1.3 Fiesta (I was 19, leave me alone! )

[anton88]

No need to be ashamed - we all have to start somewhere (i had a 1 ltr fiesta MANY moons ago as my first car and fitted a pankacke air filter - sounded cool at the time )

With the @, ive fitted k&N filter and drilled 4 extra holes in the top of the airbox, plus removed the air resonator chamber from the original opening so its just a hole now (Not sure how the rdo7's look as they have the airbox at the top of the engine).

There is a definite increase in induction noise, plus with the exhaust it makes a lot more noise now + i've re-jetted the carbs to give more fuel to compensate for the extra air going in.

[RD03 Barbie]

Anyone know a reason why the K&N filter for the RD04 will not fit an RD03? WEMOTO lists the filter only for the 750.
Anton88 says he rejetted for the mod and drilled the airbox. How much did you up-jet Anton and how ,where and how many holes did you drill?

[anton88]

Hi,

I first of all removed the air chamber thingy that fits onto the back of the airbox - Honda put it there to reduce air resonating i think - but i know better

Then drilled 4 or 5 10mm holes in the top of the airbox cover - so the extra air still has to go through the filter -NOT directly into the airbox.

I cant remember which is which, 1 of the carbs uses bigger jets than the other, but what i did was fit the following :

122.5 and 127.5 main jets. I left the pilot jets alone, but i did put a small washer under each needle (under the diaphraghm) from a radio control model shop as they sell reeeely small ones Also drilled out the slide holes to 4mm - supposedly this gives a quicker throttle response (beware - theres only a certain hole you drill on these - NOT all of them).

The bike runs fine (this is with k&N and free flow exhaust) - i sould really get it dynoed - id say its probably running a bit rich - i'd rather have that than too lean Anyway, it hasnt blown up yet

I take no responsibility if anyone copies what ive done to their carbs/engine - i havent really got a clue what i'm doing - im just a born tinkerer - sometimes it works and sometimes i break things from doing this sort of stuff So if you break your bike - go cry to someone else


Cant offer any advice about the difference in the rdo3/4 airfilter - i thopught they were the same

[RD03 Barbie]

Just in case anyone is trying this at home. "keywords" content="Honda XRV650 Africa Twin, AIRBOX MODS"
The continuing saga of the RD03 Barbie.
Long story short; got the new carbs in with 125 and 130 jets, K&N filter, Marving Exhaust.
Running too rich with these standard size jets. My old carbs had 115f 120 r with all other jets and neddles etc identical.
Fluffiness was most apparent at 1/2 to 3/4 throttle pulling from
4 to 5,000rpm
Rather than re-jetting down today I chose to try adding an orafice to the airbox.
The RD03 has the airbox behind the engine and the air enters through a pipe that finishes with a venturi that swirls the air around the filter. I figured that the boffins at Honda must have had a good reason for creating this airflow pattern and so cut a 1" hole at the front bottom of the airbox opposite the existing inlet and fitted a second pipe with the same kind of flattened configuration as the original the pipe, both encourage the air to swirl counter-clockwise and should not interupt flow as simply drilling holes might.
I took the bike on the road to check the difference and popped a wheelie coming out of the drive.
Seems to give better carburation all through the range and not just at the middle where it was stalling.
I will run it for a bit and see what the plugs say but it has given a good boost of power for sure and pulls in the 1/2 to 3/4 open much better.
Just thought I would share that. The sealant on the box should be about dry now so I will go for another blast.
P.S saw this Italian site with some good bits
http://www.boano.com/special.asp?mod=no