Weber Jetting - Ben Wright

Josh · backyard mechanic Joined: 04 Oct 2001 Posts: 602

I got my extractors and 2" exhaust put on 2 weeks ago now and I am not happy with the way the carby is set up. I have a stage 3 Crow Cam and Port and polished head with slightly oversize valves and I still have a fair bit of low end toque BUT when I open secondarys at about 3000Rpm it doesnt seem to do much at all. It sounds like it's maybe not getting enough fuel when secondarys open??? This would also stand out after getting the extractors, Yes? Anyway Could ben or someone please tell me what jet sizes I should be using and what order they go in? Also the air corrector jets? Sorry about the long post. Josh

TXcoupe · petrol head Joined: 05 Oct 2001 Posts: 1675

one way is to get an arrangement of jets roughly going two sizes down and two sets up from wat u already have. then make slight adjustmnents in the secondary barrel. If i remeber i put both the same size jet in each barrel. run the secondary maybe one size down from wat u currently have so if the number is 150 run either a 145 to see if any change or a 155.
The air corectors go for either 165's or 170's as the number gets bigger the leaner they get i think with the air correctors. If u have a chance get it to a dyno especially to someone with some exp. with webers and 2L escorts. jets shouldnt be a problem as the off the shelf holley jets should fit as the carby u have does say holley in the fuel bowl.

Ben Wight · backyard mechanic Joined: 04 Oct 2001 Posts: 946

Hey Jrosh,

try the standard jetting, its listed on my website somewhere I think, there is a link to it in the links section.

If you already have those specs, then you need to hook up an oxy sensor to your exhaust, so a dyno shop is the best bet. Without it, you are pissing in the wind with your pants on.

Ben WIGHT.