I need some advice. I have a 1980 kz650 with pod filters and a stock exhaust. I have read TONS of forums and looked all over the internet and I see that with my set up the math equates to between 0 increase and +1 on the main jet... which doesn't even justify an increase in pilot jet. My question is: does anyone have pod filters and a stock exhaust and have experience with the jetting? I am concerned I am going to re-jet it with only one size increase and see no difference at all. Second question: am I inhibiting flow with the very restrictive stock exhaust? I could just make a custom exhaust before jetting, then go with +3 or 4 on the main jet and +1 on the pilot. Thanks for the advice and help everyone.
Photos from Erik Stillwell's post
my $0.02-would have kept the factory airbox & changed the exhaust, then gone +2 on the main, makes for smoother power & easier to tune carbs. you have the earlier style carbs which react better to pods than CV-style, but the factory airbox wasn't as big of a restriction as the exhaust was
That's what I keep hearing. Unfortunately the bike came in boxes and I didn't have the stock air box. I guess exhaust comes next.
do the exhaust & jet to suit,sounds like you're on the right track, short of a factory airbox, try to find something that mimics the factory rubber boots from carb to airbox, they created a pretty decent velocity-stack effect on airflow going into the carbs.
Kz650 info forum has a thread
Where everyone lists what altitude they live at, what intake/exhaust they are running/how many turns on the screws/what slot on the needle and what jet sizes they use, it's a great starting point to work from. I'm running kn pods with a mac 4-1 but forget what size mains/pilots (79 z650). I'm pretty sure I have my stock air box somewhere to if you're interested