Badfighterpilot

Im building a 12a BP fuel injected and turbo, But Im going to need to use the stock setup for at least a few months once the car is finished. The carb and intake have been fully emission deleted and sealed up. But I need to find the idle jets, those loong need jet looking things all i can find is the main jets. From what i know all you need to do is change the idle jets for bigger ones and crank the fuel mix all the way up.

peejay

From my experience, the throttle plate will need to be open so far at idle due to low vacuum that it won't idle on the idle circuit.

Idle jets are on top next to the main air bleeds..

Benjamin4456

Nikki's don't have idle jets unfortunately. Everything is intertwined so if you mess with the primary no.2 air bleeds (the closest thing to idle jets we have) you'll also affect the operation of the rest of the carb.

I don't have any experience with bridge port motors, but if they really create such little vacuum then I'm not sure what I'd do. With stock jetting the mains will come online around 2k rpm under no load - granted this is also on a stock or mild ported engine.

If you need to richen the idle mix you can do so with the mix screw. Technically however this doesn't really "richen" the idle mix, rather in increases the proportion of the idle mix that is administered. The idle mix is determined in combination by a jet that is pressed into the baseplate (don't mess with it) and the no.2 primary air bleeds. Decreasing the size of the of the no.2 air bleeds is common on modified Nikkis to help with the secondary transition and aid in chokeless cold running as it richens the actual idle mixture. It's pretty common in fact to just swap a spare set of the nickle-plated secondary no.2 air bleeds over to the primary side for this (I believe they're 60s if memory serves correct, often called "nickle-plated 60s").

That said, I would suggest not messing with anything until you've, one, tried to run the engine, and two, done a lot more reading on the subject of modding Nikkis. A wideband will also be invaluable. It's been a while since I've touched a Nikki so I can't offer any too specific advice anymore, but look for posts from Jeff20B. Sterling was a pretty big name in Nikki modding as well, although I recall not agreeing with all of his findings. I have my own Nikki modding thread too (linked in my sig), although it's by no means a how-to, more just documentation of my trials and tribulations.