Air System Upgrades

[maestro]

I recently ordered those little chrome EMGO individual air filters (4 of them) for my 78 XS11E as well as a new set of MAC 4 into 1 megaphone exhaust. I had a terrible time trying to decide if I should go with the individual filters or just get a K&N that would fit my factory airbox. One mechanic told me one thing, the next something else and so on. So, I went ahead and purchased the individuals for something different. I went to change the air filters out today and guess what I found in my airbox? You got it, a K&N filter!! Who would have guessed?!? So, my question is, should I leave the filter that is there or would it make a difference switching to the individuals? Either way I will most likely need to re-jet since I am changing to factors instead of one. Any advice related to this would be a great help!!

[Mike Hart]

Maestro, strike up the band -

The info that you want is here specifically for rejetting.

Not to single you out, this happens all the time - see this briefly.

Then have a look here for tips on how to find info

I hope it helps you with jetting, and I hope it helps others who have questions. A lot of questions have already been answered, though many haven't, and it's usually worth a look. No offense to you I hope

Not covered in the rejetting tip is altitude. Coming soon at a forum near you.

[maestro]

I wasn't asking about re-jetting. I already know what I have to do there. My question was, is there an advantage to running individual filters over a K&N that fits the factory airbox? That was my main reason for the thread.

[Jdwags]

to individualize or not to

I had a customized filter on the Mongrel, and it really starved it for air,

I put the air box back on it... and need a filter for it, but I am considering individual's if for no other reason, is its alot easier to get to the carbs....

I do wonder how the jetting will change. .but thats not my only quirk right now.

[Mike Hart]

Originally posted by maestro
My question was, is there an advantage to running individual filters over a K&N that fits the factory airbox?

well that question hasn't been asked lately

Not sure on cf/m flow figures, the filter suppliers might have info on that. Someone here might now which flows more air. I'd guess the indiv. flow more.

I think the biggest advantage to indiv. filters is how much easier it is to get the carbs off/on. They sound really cool, too, nice intake noise!

Advantage to k&n? If you care about keeping the bike stock? Less likely to get wet in a downpour or when you are washing the bike? Denny runs individuals and hoses the heck out of his bike, doesn't seem to bother it...

[Bill__Woods]

just forget the air filters and run velocity stacks. hell on the jet needles & needle jets, but oh well. I imagine you get less turbulence with the stock airbox and the K&N, vrs the individual filters. turbulence is not a good thing, as it steals horsepower.
let us know of your findings.

[maestro]

If I put on the individuals, what do I do with all those extra "hoses" that are running to the factory airbox? What are their purposes and how will it change if they aren't connected?

[Mike Hart]

bowl vent hoses on E?

none of us replying on this thread have a Standard so I can't answer that one. I think there are 2 bowl vent hoses? and hmm I'm fuzzy on that, been to long since I was hands on F carbs..

I hope someone with an E gets back to you on that.

[oldnortonrider]

Originally posted by maestro
If I put on the individuals, what do I do with all those extra "hoses" that are running to the factory airbox? What are their purposes and how will it change if they aren't connected?

3 YEARS ago, I wuz wondering what to do with those two same
hoses. Assuming, you're talking about the hoses @ the tops of
the float bowl chambers, which are right above the T
that puts fuel into the chambers.
They're called vent tubes.....breather tubes......; ...when the fuel fluctuates up and down; the amount of air changes in
there, also. Has to come from somewhere. (I think I have seen
them called by other names, in one of my manuals).
Also, I believe, it has something to do with (??) maintaining the
same/correct atmospheric air pressure, inside the chamber, as is
on the outside.
Can't plug 'em up , or cap 'em off. no.
What I did on mine; works perfect : I put small in-line plastic fuel filter on the end of about a 6-8 inch
clear piece of fuel line, for to be the tube for it to breath/vent from. The idea of the fuel filter was so I'd know a
dirt-dobber wasn't going to crawl into the tube to stop it up,
or anything else to "fall" down in there. You can aim the tube(s) any which way; preferably upwards. I don't guess it would make
any difference, really, as to the length.

If this ain't the answer; I'll have to think of some "other tubes".

81SH
79F

[sixtysix]

OK I have a standard, but it really doesn't matter. The bowl vents on the 80 and up XS's can be just looped over and tied someplace, they need to be left open. I have seen guys who just pull them off and leave the t's open. Even new bikes just loop these forward and route them down with the other vent tubes. Next is the breather for the crankcase, most 4 into kits come with a filter to put on this hose or you can buy a nice chrome Harley one for $6-$8 like I did.