Question on throttle

[ZMR25]

I am building a SPG Predator engine and it runs great without the air box but when I put the air box on it seems not to take the throttle as good....Busting up when hitting the gas....Take top off and runs fine...Have a 35 main jet and 22 low speed jet.....Should I lower both jet sizes or what?....I bumped timing up like 5 degrees.....Has factory cam....Lift is at Ex 238 int 234...I am out of jets right now but if that's what I need I will get some....


Thanks In Advance....

 

[DirtRacer7]

Most predators with a stock air box and aftermarket cam, SPG legal setup will be on a 32 main jet and 25 low with a ruixing carb. Or close to that.