weber jets. ATTN Russ-D

what jet should i be runnin in my weber? i dont know which one is in there right now but its doesnt seem to run right. it idles bad.

it waz a used weber i got off ebay. its a DGAV with tha upgraded electric choke on it already.

i would like to know which Main Jet and the Idle Jet.

Thanx N|ck

what is your altitude?

umm, idle 50/55 main jet 120/130 should get you close. I would probably see if it can be tuned first. Start with a CLEAN carb (you'll need a rebuild kit, 30 bucks, and about an hour). Turn the mix screw all the way in, then back out two and a half turns. Start the truck, if it wont idle turn up the idle screw, if it idles high turn it back down. When the engine is warm and the choke is open, adjust the idle to about 1000-1200. Disconnect and plug the vacuum line to the advance on the dizzy. Disconnect a decent sized manifold vacuum line that is close to the carb base and hold it closed with your thumb.

The next part is deceptively simple. move your thumb and give it just the smallest vacuum leak. If the idle speeds up, your mix is rich and the extra air is making the engine speed up. Turn the mix screw in. If the engine slows down, it is lean and more air is making the engine stall. Turn the mix screw out. If you find yourself turning the mix screw all the way in, your idle jet is too big. If you turn it all the way out and it is still lean, it is too small. When you turn the mix screw in or out, the idle may change, so set it back to 1000-1200 and try again.

Main jets are tougher to tune. You would benefit from a air fuel meter, see if a ricer buddy has a spare laying around. Now the Mazda has a narrow band O2 so WOT readings are useless. BUT you want to see how the main jet is performing so find a nice long uphill stretch. You want the A/F to be just a hair lean when climbing a hill in top gear at around 50mph and normal at cruise. If it is rich, go one size smaller if lean one size bigger.

Some people buy a range of jets to have on hand for season changes. Some people just turn the idle up in the winter and down in the summer.

yeah i dont know my altitude.

but i will try tunin it forst.
Also. i did buy a rebuild kit. and a new brass float. when i bought it. and rebuilt it.

Thank you for ur time Russ. i will see what tuning will do. hopefully run better.

Thanx again,
N|ck

I'll try getting into my carb on sunday and listing my jets, right now I'm running almost the same jetting as the Ford Pinto, which is working pretty good. Could still use some tuning for better power but runs solid and gets fairly good gas milage.

^ ditto.

My 5200 is running the factory Pinto jets. runs pretty good, a little on the rich side, but still getting 24mpg city and 26highway.

make sure you dont have an idle cutoff solenoid on the carb or it wont idle

yeah see i dont know what my carb is originaly off of.

and it does have a idle cut off . but its not hooked up.


Thanx N|ck

It will idle but you'll have to crank the piss out of the idle setting. The anti-dieseling solenoid needs to have 12 volts to it with the key in the run position. It's purpose is to pull the throttle plate into the idle position when the key is turned to the run or start position, when you turn off the truck it pulls the plate completly closed so that the truck won't diesel or try to keep running after you turn it off.