New airbox= new jetting?

[87_shee]

Hey guys, My G/F got me a aluminum aribox from CFM on ebay for christmas. Now i ran a stock airbox with lid on and a uni and 300 mains, stock pilots, clips in the stock position and the bike worked fine, Nice tan brown plugs. So im trying to figure out how much i will have to up the mains and pilot? I know the only way to know is a plug chop (which i will do) but i was just looking for a starting point or any info from someone with the same airbox. Thanks

 

 

Oh yah my mods are

Fattys

coolhead 22cc

vitos reeds

boss intakes

stock carbs

66mm bore

 

 

Its also around -5 to - 10 celsius here and im at sea level

Edited December 26, 2007 by 87_shee

[Michael Jackson]

i would try 300 mains, stock pilots and needle on 4th clip down on a piped banshee, open airbox, at sea level, 300 must have been rich with the airbox lid still on and 300 mains, no air gets in with those stupid lids on, either way of course you will need more fuel with the aluminum air box cause it has no lid, huge difference

[87_shee]

My plugs were nice and tan brown this summer with 300s in it and the temp was 10 15 Celsius.

So your telling me that with the new airbox and the temps now at -10 or -15 that im not goin to have to increae my mains or pilots??

I figured that i would have to go up at least a few sizes on the mains and maybe 1 size on the pilots.

 

I guess i will have to wait until the local shops open and go get some jets and figure this out myself.

 

Anyone else have any ideas?

[Michael Jackson]

of course you will have to bump your mains up when opening the air box up,i never implied you wouldnt, but thats assuming it wasnt already rich, only you can be the judge of that, 300 just sounds rich for a pipped banshee with the lid still on the airbox, pilot you shouldnt have to touch

edit - yes also need to fatten up jetting for the winter, i run a 280 in the summer and 300 in the winter on a piped shee with no lid, im at sea level about , i just dont see how with the lid still on you are running the same size main jets in the summer, that i am running in the winter and i have no airbox lid

Edited December 26, 2007 by Michael Jackson

[87_shee]

Well i just put it together and tried it out with the 300s and its running really lean, the plugs were almost white and i only had it at 3/4 throttle.. I goin to try some bigger mains but im starting to think i might have an airleak somewhere because it revs up fine but takes it while to rev back down....so somthing isnt right...unless being really lean would cause slow rev down.

 

besides that i really like the look of the new box...much cleaner than the ugly stocker.

[Michael Jackson]

sounds like you have an air leak

 

even if the 300's were a tad lean, it wouldn make it do that, for your mods and elevation which are about same as mine, it should be damn close to a 300main,

[87_shee]

It always seemed to be slow to rev down and i have driven like that many times with zero problems, my intakes are not in the best shape but there are no big cracks in it, i already ordered new billet intakes so when i get those and new reed gaskets so i will be sure there is no airleak in that area. where else can it leak? Im pretty sure its not sucking air from the head or the base gasket. Is there anything besides an air leak that would cause the slow rev down?

 

I am goin to make sure there are no air leaks tomorrow and then il try some 320s and see how that goes.

I wonder if this box will flow more than a stocker with no lid?

 

Thanks for all the input

[Michael Jackson]

how about where the new air box meats the intake?

and a box is a box, weather is aluminum or plastic.. is it the same basic design, just a box with no top? what kind of air filter do you run,and is there an o ringed adapted plate fixed to the box airtight with an air filter that seals with a hose clamp?

[87_shee]

Well i was out in the garage and i checked to see if there was an airleak and i relized i forgot to tighten one of the intake boots all the way, which was causeing the slow rev down It wasn't to bad i caught it right away, anyways i tried it out again and the plugs are burning pretty light brown and again i was only about 3/4 throttle in 4th gear. So i think either a 310 or a 320 is goin to do the trick. and yes everything else is sealed tight, the box uses 2 pod filters which are all sealed tight. Im also thinking im going to go to a 27.5 pilot cause it seems like it wants some more gas in that throttle range.

[brian]

pilots really only control the idle mixture- 1/8th throttle.

did you have to turn in the air screws alot ?

if not, the pilot jets are prolly ok.

if you feel that it needs more fuel in the lower range you prolly

need to raise the needle (lower the clip one notch toward the pointed end).

 

then, if i were you, i would get the mains you think are needed, put em in, and

do a plug chop. but make sure you do it just as described in the directions. you

are not looking for tan or brown all over. just a band at the base of the insulator.

its the only way to isolate the circuit you are working on. keep in mind that you can

do a plug chop test for midrange as well, just do the same thing at 1/2 throttle

instead of WOT.