Shortening the Carb air intake.

[commitedskater15]

Not a build thread or a how-to. But i have looked endlessly and cannot find any information or threads on how one might go about putting the airfilter almost directly ontop of the carb intake as opposed to having the filter about a 1/2' above the carbs. Reason I'm asking is so that I can make room for a "real" gas tank to take the place of the false tank.
Thanks, Art.

[CYBORG]

"real " gas tank????? I thought the fuel tank on the goldwing was "real". I mean, it holds fuel, and provides a delivery system to the carbs. Does it get more real then that?? If the fuel tank that is stock on the goldwing is not "real" then it stands to reason the "air filter" isn't real. Which makes me think maybe the carb system isn't "real". So I guess the answer is to convert the whole thing to a single carb design which sits lower.

[commitedskater15]

Please excuse my use of the word real.
Thanks, Art.

[RB]

Cut off the rectangle bottom piece and re-weld the bottom of it to the box so you have the trough for the rubber seal and bolt holes??

[Whiskerfish]

Some have gone to a custom flat style filter. Can't seem to come up with any links right now but I have seen it here. It would require fabricating/adapting the lower intake box flange to a flat filter system.

[mrtwowheel]

Just thinking that any change to the intake on CV carbs can cause a drastic change in the vacuum that these types of carbs need to work properly. Just changing the size of the filter area would change vacuum flow. I'm just leery of changing anything about the fuel and air, even the one carb setups.

Scott

[NCScooter]

Just thinking that any change to the intake on CV carbs can cause a drastic change in the vacuum that these types of carbs need to work properly. Just changing the size of the filter area would change vacuum flow. I'm just leery of changing anything about the fuel and air, even the one carb setups.

Scott

Having read thru Mike Nixon's explanation of CV carbs(> http://www.motorcycleproject.com/text/h ... ork_v3.swf <), I'm not sure that the filter is going to have that much influence. I'd love to have him or Randakk comment on this. Or any of you other gurus. Thanks.

[robin1731]

I ran a small round open filter on mine for awhile. I think it is about 6" in diameter and 2" tall. It is for a car. It did make a difference in how the bike ran. Not drastic, but it does run better with the stock air box.

Found a couple pics of my filter.

[sunnbobb]

With you on that Robin, I noticed better performance with the stock air box.. I would think you could do the welding trick though.

[gregforesi]

It would seem to me that there are two design criteria to consider: The flow through the filter element and the size of the stock snorkel opening. Changing either could have an effect on the stock CV' s and lead to what SunnBobb and Robin have noticed regarding performance with a modified intake.
Any intake mods that provide the same vacuum signal (or curve since it changes with rpm) just ahead of the carbs should allow the same performance as the stock airbox.
Some coil mods have required the snout of the airbox to be shortened. I would suspect that losing the bellmouth of the snorkel would have at least a small effect on what goes on. It's been noted here many times that these are fussy about intake mods but tolerant about exhaust changes. A low airbox is certainly doable with a bit of foresight and thought.

[robin1731]

snip..............
Some coil mods have required the snout of the airbox to be shortened. I would suspect that losing the bellmouth of the snorkel would have at least a small effect on what goes on.

I have done that mod. I cut mine back quite a bit mostly to make it easier to get the air box out. That mod I have noticed made no difference. On a few different bikes.

[jdvorchak]

Modifying the air intake and putting a gravity fed fuel system on it? At least it will look cool as everyone passes you.

[CYBORG]

You have to think Honda had a reason for building that air box the way they did

[John Schmidt]

FWIW, I adapted a "real" gas tank from a Valkyrie on to my '84 Std. and use the entire OEM intake system; filter housing & filter, carbs...the whole 9 yards. That gives me a tad over 5 gals. in the tank and lots of room under the seat, plus I think it looks kinda neat. I have the tank hinged at the back end so if I need to get to fuses or filter, I simply unbolt the front mounting bolt and tip it up. I made a platform for the regulator and fuse box that bolted to the original hole the front of the OEM tank inserted into. Fuses are mounted on top and the regulator underneath. It's all wide open under there so should get plenty of air flowing over the regulator to keep it cool. I agree re. Honda's engineering on intake systems. On the Valkyrie Tech Board over the years there have been numerous attempts to "modify" the OEM airbox, all to no or little avail/improvement. Many have cut down areas, cut off portions, drilled holes, the complete gamut and most have returned to buying an OEM replacement off EvilBay to replace their "modified" unit.

Re. the tank, it's off the bike at the moment, got it for $00.00 and needs some real love before using it but can't argue with the price. With a manual petcock it flows good and it appears I won't need a fuel pump since I've already run the engine at high RPM on gravity feed only. Gravity feed worked to feed six cylinders, so it appears to also work to feed only four. Time and miles will tell the story.

[robin1731]

All CV carbs are affected by the air flow. Doesn't matter if it Honda, Kawasaki, Suzuki, whatever. I get guys with Kawasaki's that have CV carbs and want individual pod filters on them. It can be done with a jet kit. These come with usually new needles, different jets of course, and a drill bit sometimes. They don't make a kit for a GL though.