Cone air filters question?

[cb1ontherun]

Hey i am installing sone cone filters on each of the carbs.  Other than putting 40 pilot size and 130 main jets.  I notice there are two hoses that connect to the air box and 2 metal tubes that come out of each carb head " where you connect the cone filter to.  Do i plug any of the hoses or tubes???  Some insight would be greatly appreciated.  this is a 89 honda cb-1 400f.

[a_morti]

Hey i am installing sone cone filters on each of the carbs.  Other than putting 40 pilot size and 130 main jets.  I notice there are two hoses that connect to the air box and 2 metal tubes that come out of each carb head " where you connect the cone filter to.  Do i plug any of the hoses or tubes???  Some insight would be greatly appreciated.  this is a 89 honda cb-1 400f.

Dude you are in for a world of pain. 40/130 is a complete random guess. Getting it to run well will take far more work than it's worth. Says me who is in the middle of the same planet having changed air filter to foam, cams and can. But heck, knock yourself out. Also of you're doin this, get nc23 cams or you're wasting your time since the nc27 ones are too restrictive.

If you want them though, I might have a set of 40 pilots spare.

The two brass tubes on the carbs - one is air intake for the slow jet at tickover (bypass circuit). I think the other is to do with the choke but am not certain.  

The two off the head onto the airbox are breathers. Fit a mini cone filter to stop flies getting in.

Don't plug any of these holes!!

[cb1ontherun]

there must be someone who has tried this and gone all the way lol.   for perfect size jets

[a_morti]

there must be someone who has tried this and gone all the way lol.   for perfect size jets

Not many, because it is such a pain in the ass to get right, or even close enough to right that the bike will run decently, for such minimal gains, that not many will bother. Same as there are not many who have fit nc23 cams, so I am on my own with trips back and forth to my local dynojet centre. But from the limited success I have had so far, I can tell you switching the cams is by far the easiest, and probably only, way to get over 55hp from a CB-1. Without resorting to flatslide carbs, anyway.

[clarkdw]

Even setting the jetting on the dyno is a best guess for the operator. As soon as you take the bike out on the road the jetting requirement can change substantially based on air pressure changes due to the bikes motion. Lots of owners have tried removing the snorkels on the airbox or removing the front panels on the frame looking for better airflow to the carbs only to regret it. The CB-1 has a very fussy induction system that generally does not like to be messed with and lets you know that by giving all kinds of quirky surging and flatspots unless you are willing to put in lots of time and experimenting. Very few owners will be able to offer any helpful advice other than dire warnings and I have yet to see anyone who has hard numbers from a dyno comparing before and after with induction system mods. If you want to do it for the noise, at least it will sound faster.

[dasch]

I got cones, can't really tell if it's running better or the same, there's a slight flat spot on very low rpms, but I get the top speed easily. Intake sound is awesome. Can't recall now how large the jets ended up, search my posts, it's in there somewhere. I also had to shorten brass tubes a bit and raise the needle some. I only swiched to cones to make room for electrics under the tank in further steps of customization. If you're happy with how it runs now - leave it be.

[Drewski]

As above -take 'em back to the shop. "World of pain" sums it up well.

[dasch]

I forgot one more tip: once installed - you have to be reeeeally carefull when removing and mounting back the gas tank. Cones that fit your carbs are like 7cm long, that is around 2mm away from the bottom of the tank. I had to remove the rubbery stuff from bottom of the tank, to get some more room.