1987 318 Tuning with Summit Carb

Bewy said
I agree with others: the idle jets seem to be huge. Can see no reason for them being that large for a carb designed to go on a relatively stock engine. Is 0.046" a misprint & they are actually 0.036" [ more like it ]?

You see the booster pic in post #25? The 1/4" diam brass tube? The small tube inside the tube [ visible in the pic ] is the idle jet [ fuel ] . You need to get some numbered drills, use as a go-no-go gauge & see if they are 046. If so, you should reduce the area to about 0.032". You do some calculations to find a piece of wire that will reduce the area. Since at this stage you are trying to clean up the idle, you should be able, for a short test, to scrunch up a length that will sit inside the 1/4" tube & poke one end of the wire into the jet. If the problem is solved, then a more permanent fix is pretty easy.

The .046 is the two circled brass jets in post 25. I can change those out. Those allow air in and mix with the fuel from the idle circuit. I had intially put in smaller diameter ones in thinking it would make it leaner, but I had it backwards. Bigger air bleeds should lean out the mix.

I'll get some numbered bits and check the inner brass tubes. No clue what their diameter is. From what I'm researching, it's better to not mess with the air bleeds and only change the fuel being delivered to the idle system. So like you said, I'll measure the tubes and maybe throw in some wire to restrict fuel delivery to the idle system. And go back to .043 air bleeds.