lunchbox question!

[greaseman]

Been searching for a while now but couldn't really find anything that was relevant enough to use, so...

Just threw in a lunchbox air filter and rejetted the mains to 150, and i'm running a V&H exhaust. I'm also always running on prime. However, I went out for the first ride today and when I take it anywhere above 6000 rpm, it would hiccup and have the symptoms of fuel starvation, so i'm assuming it's fuel starvation (/too much air because of the new filter). What I'm about to do is take out the in-line fuel filter and run it with only the petcock filter. This is the first time this has happened to me though so I was hoping that people with some more experience with the lunchbox could point me in the right direction before I do something I regret. Appreciate any input! 

[5thAve]

yes, it is fuel starvation. Usually happens at highway speed (say, a sustained 60-75mph?) This is the vacuum petcock not being able to flow enough fuel.  Search this forum for "vacuum petcock" and you will see several discussions, including ideas for modifications to the stock petcock (not too difficult). Only ways around it are modifications, or an aftermarket manual petcock (you will have to turn it to "off" after every ride, like in the old days). Example: Pingle makes a petcock for racing. Can be easily fit to our bikes, or get one from a Honda CRF250, I think... better do some Googling to check my facts though -- I'm going from memory here.