i just drilled 35 1/4" holes in my airbox lid, should i rejet it or no? i have had the mods in my sig rejetted and im wondering if i will need to do it again since i drilled holes. Also, i think its jetted a little bit lean already because ever since i put on my pipe and jetted it, its been hard to start the bike cold, and somtimes it back-fires. Thanks for any help.

 

well, if its lean still, u might need to jet it down smaller, u wont have to rejet it any bigger for the holes if its back firing, that means too much gas, its not all burning, if this persists, jet it down anywhere from 5-30, depending on how bad it is

 

if it is lean, jet UP, not down. when putting holes in the lid it leans the mixture out meaning you need to go LARGER on the jets.

 

so maybe since its already a little bit rich (backfiring) the holes in the lid will equal it out so it will be leaner and jetted better. does anyone know if its hard to start does that mean its rich?

 

if it is hard to start it is probably lean on the pilot jet.

 

hmm well ill give it a shot and try it out with the jetting now. If i notice any changes or anything unusual ill post again. Thanks for the help

 

those jet kits don't come with pilot jets. you can try turning out your fuel skrew on the bottom of the carb 1/2 a turn or so and that will richen it up a bit. the lean condition on the pilot jet/fuel skrew causes some popping. the fuel skrew is a fine tune adjustment for the pilot jet. however, most people i talk to run a 40 or 42 pilot jet in their 300ex and 400ex