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You, sir, are a king. I'm going to try these things tomorrow if it isn't pouring.

Hmm. I'm going to try that and see if it works. I'm seeing less and less consistency on the idle mixture screw. I can get it to run super choppy if I turn it in too far, but once I back it out and it's running better I can keep on backing it out and there is virtually no change. I'm also seeing the RPMs jump around at idle. It's like the truck is trying to work it's own issues out. I made a video today of what it does. This is me sitting with the engine warm, not touching the gas or anything. Also, I'm not sure if this hose (that seems to lead from the intake) is supposed to be connected to anything or if it just is a vent hose. I don't feel any air flowing out or sucking, and when I cap it with my finger it doesn't have any noticeable effect on how the engine runs. Figured I'd post it and see if it raised any red flags with y'all.

Thanks Mike! This has been a huge help! I've been fiddling with it the past few weeks and can't seem to get it to idle any lower than around 1200 but it seems to be alright. The air mixture screw doesn't seem to like being turned in too much, but doesn't really start idling any rougher when I back it out...so I'm just kinda working towards where I think it should be when I get that rough idle turning it in. That said, it's tricky to get it to the right spot when it's cold vs. when it's hot. I can tune it all day when the engine is warm but then when I find that magic lowest idle spot and let it cool down it's too low, so I turn it up and then it idles fast once it's warm. Tough to find that happy medium. Gonna keep playing with it this weekend and see where I can get it at it's best. I'll try to take some video and see if maybe you hear something that I don't. Again, thank you! You've gotten me leaps and bounds farther than I'd ever be able to on my own!

I can hear the light click from the carb when turned to the "on" position. Rode it to the gas station. Filled the tank up. Died the whole way there and back once it was warm, per usual. Took it home and parked it. Wouldn't stay idling so I adjusted the idle screw in a half-turn at a time and would fire it up and try to get it to idle and still no luck. Someone had removed the factory seal that blocks the idle adjust so that tells me it's been tampered with in the past. I turned it in a total of 2 and a half turns and saw no effect, so I set it back to its original setting (backed it out those 2.5 turns) and threw in the towel. Not sure what to do now. Le sigh.

I'll try to see if I can hear the light clicking sound coming from the carb as soon as I get home from work. Say everything is cool and I have to turn the idle up. Would I pry off that cap in this photo and turn the screw in? Or would I adjust this "idle compensator" that's pictured here? Thank you again for your help!

Hi! I'm new to the forums but have been lurking for some time now. I recently bought my first Datsun. An '83 720 King Cab 2WD with 70K original miles. The guy I bought it from flooded the engine and killed the battery right before our eyes while he was trying to start it so we got it for a really good price and towed it home. I replaced the plugs on the left hand side (I couldn't access the ones on the passenger side easily) threw in a fresh battery and it fired right up. A little smokey at first but after a minute or 2 the smoke disappeared. Took it around the block a couple of times and it was great. Shifts like a dream, quiet, and everything seemed perfect. Then I took it about 3 miles down the road to meet up with some friends. Parked it for about an hour and then went to grab some food when all the sudden it died out as I was taking a U-turn and dropped it back down to idle. Started up easily again, which makes me think that's not necessarily vapor lock, but it kept dying out at every red light and stop sign until I got it home. Again, started right back up when I'd turn the key, but just wouldn't idle. Now I'm experiencing that same issue every time it's warm. It'll run fine at first but when it goes back down to idle after the engine is warmed up it'll die when I come to a stop. I have extensive experience with 2-stroke mopeds, motorcycles, and other small carbureted engines but I can't figure this one out. Is there some type of switch that changes the idle point when the engine is warm? Should I just turn the idle screw in a little bit so that it idles faster? That seems like a band-aid, but I'm willing to try it. Also, where is the idle screw? Do I need to remove the air cleaner to access it? Thanks in advance for your help! I'm super excited to drive this thing more when it doesn't die out all the time!