Rochester monojet

[airbrushguy]

My 71chevy C10, 250 6cyl with monojet carb/manual choke runs, idles badly. Will not idle in gear when choke is off. Seems to run rich. Which adjustment screws do what and how should they be set? Took carb apart, needle was not even attached to float...fixed. Float was set too low...fixed carb rebuild kit was not easy to follow...any thoughts?
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[BiggSixx1970]

My experience with these old trucks is limited, as I am young and this is my first project, one of the first things I did when I bought my 70 c20 was give it a good tune up, starting with my carb, which is a rochester monojet. The carb kit came with the gaskets, bearings, and replacement valves, but no float, had to buy that separate.

If your float is neoprene, check it for splits and cracks, that will cause your carb to not give the engine the correct amount of fuel, an all brass replacement ran me under $10 I thought. I didnt replace the ball bearings that came in it, a friend told me that was pointless as long as you gave it a good soak and blew all the passages out. if you replaced all the carb gaskets and got it all torqued down right with no leaks, you might need to adjust your carb

[GuyO]

I suggest you warm your engine as best you can, then set dwell. Set timing to 8 degrees below TDC with vacuum advance disconnected. Adjust idle speed (located near throttle linkage) to 600 rpm. Turn idle mixture (located on carb base) in until the needle seats, then back out 2 full 360 degree turns. Re-adjust idle speed to 600 rpm with engine in drive (AT). Turn idle mixture in 1/4 turn at a time until idle speed drops, then back out 1/2 turn. Reset idle rpm to 600. Let us know how you make out. Once you have done it you will realize what a great and simple carb the monojet is!

[airbrushguy]

When you say "Reset idle rpm to 600" do you mean with it in drive?
Because if I do, it won't shut off without dieseling ("pre-ignition".)

Setting it at 600 in drive, means 1100 in park.
Thanks

[ole dollor]

sounds like you have a vacuum leak some where. if it has to be choked to run, and at 600 rpm in drive and 1100 rpm in park, i set mine at 750 rpm but mine is a standard trans....could be intake gasket, carb. base gasket. pcv valve, crack in intake....take some carb cleaner spray, and spray around the gasket surface's and see if it runs better and smooths out. then you will know where to start .