Air box?

[Evolution6972]

I have a honda cb400 on my kart. It seems that when I try to run with the cone air filter the engine suffocates. I am considering building an air box and pipeing the carbs to it. I usually drive on dirt trails. What's your thoughts. In my head I'm thinking a big car or truck air filter with a box cut to hold it.

 

[landuse]

You should be getting enough air through those filters IMO. I do know that those cone filters let a lot more air through them (and also dirt) than other filters. Some people even put stockings over them to catch more dirt

 

[OzFab]

Is it suffocating or starving? It could simply be a case of bad filter choice; how does it run without the filters?

 

[Evolution6972]

With filters the more you push the throttle the more it bogs down to a put put put. Without it screams. Drives so great without

 

[Evolution6972]

And yes I have cleaned them I washed them and let them dry and then I even blew them out with air compressor. I don't even understand how they are giving problems.

 

[landuse]

Please use the edit button on the bottom right of your post if you want to add more info. It saves us having to read multiple posts.

 

[fowler]

yea id have to agree with u
usually pod filters allow too much air and the engine runs lean

but your description sounds right

try putting your mouth around the filter and blowing though it to see how easy it is

the only other thing is its getting too much fuel
which is also the opposite of what usually happens

i suspect because u have the fuel tank so high it is forceing the fuel in

when the tank is full u will have alot of head pressure there

if u have a fuel tap then turn it half off and go for a run
if that fails try it 3/4 ways off

also try draining the tank and then refilling it with just 1 litre
or just a tiny bit of fuel


is this problem new or has it been around since the kart was built
did the start of problem collide with any mods done


EDIT
but top answer the origonal question a truck air filter would work
those pod filters are good for performance but are not good for engine health
they let in alot of dirt

a good alternative is sothing a ant find on google
we call them cycolone filters
they look sorta like this

u can make a manifold that runs both carbs into one and up into the filter outlet

or u run air backward though the filter
so the air enters the centre then u weld two outlets on the outside of the cylinder that align with each carb