hey,i just fitted a large aluminium airbox to my 51mm ida weber and at 6000 rpm it hesitates but will pull slowly to 8 1/2
i did drill the main jets from 245 to 250 have f11 emultion tubes and 115 air correctors.
should i drill out main jets bigger or or get smaller air correctors?or what?
can someone help me please.

 

Sounds like fuel issue. meaning by the time you get up to 6K rpm, the fuel bowl is empty. which fuel pump are you running.

also, years ago, we tried that cold air intake box (1 inlet on the passenger side and 1 driver side) but it was too restricted.

 

What is the clearance from the top of the air horn (velocity stack) to the top of your air box? Where is your air filter?

What kind of porting do you have?

What were you using for an air box / air filter before?

Were there any other changes made except for the air box / air filter?

What diameter hose is feeding the air box? A bigger picture may help; it is hard to see with that tiny avitar.

 

ok i got 5cm clearance to lid, large bidge port,filters on intake of box using same filters still(uni filter)huge 6"hoses to box, if i take the lid off it runs fine when i put the lid on it restricts it someone told me to dirll the jets, uploading new image now!

 

carter gold runing 4 psi

 

Do you have an air/fuel meter if so what does it say at 6000rpms? I'd guess running too rich, not enough air.

 

Were there any other changes made except for the air box / air filter?

What diameter hose is feeding the air box?

 

he is running 115 air/250 main. thats how you want it to be. rich on top end but he has fuel issues.