78 CB750 CARBS/AIRBOX QUESTION

[DAK750]

WILL THE BIKE RUN WITHOUT AIRBOX??? I CAN START IT AND IT WILL RUN WITH THE CHOKE. WILL IT RUN WITHOUT THE CHOKE WITH AIR BOX ON. iS IT GETTING TOO MUCH AIR WITHOUT THE AIR BOX??

[TuNguyen]

If you do not install airbox, the bike will not run good. I go that problem before. I start my CB750 without air box, the bike is dead when I take up to haft way off throught. So it is good thing to install airbox before adjust any thing.

[shabbabear]

NEVER run w/o the airbox...you will suck in a tiny rock or something and get major vavle damage and the moisture getting into the motor will destroy proper combustion...backt o the box or get the individual filetrs like the unis or the old k&n's...hope that helps....shabbabear

[Altdo]

Of course you can run it without the airbox, and depending on how the carbs are tuned it will run fine.  You do run the risk of sucking something into the carbs and totally ruining the valves and possibly engine, but it'll run... infact a few of the bikes i've built never had an airbox or filters, just carb covers.  
If you do get Pod filters to replace your airbox make sure you get ones that will clear the choke on the second pod, they're kinda hard to find.

[blackhawkrider]

It won't run right, these carbs need the vacuum created by airbox/ pod filters in order to lift the slides. There are carbs that do work without an airbox but not the ones you have. Without the box it will start and run but will go flat halfway through rev range.

[leboeuf]

hi my name is shannon
i have a 1978 cb750k and the airfilter box was broke bad and i put some air filter pods on and it runs ok except when a burst of wind hits from the side it bogs down
can this be adjusted r should i try to get another airfilter box

if any help that would be great

[Drew750]

Hi there,

No expert, but bike should run but will be very lumpy as the carbs would be set with airbox fitted. Not good practise according to manuals etc. Even a change of airbox/cone filters usually means a change up in main jet to allow for the extra air in the mixture.