Help adjusting DC-3 carb (Zenith)

There are two adjustments (basically) on this carb - What I have heard is the idle adjusting screw (has a spring on it) on the upper side of the carb and the high speed adjustment under the bowl. I need the step by step description of where to start and what to do.

Do I screw this in all the way and then back it out? What should my throttle setting be when I am adjusting things.

Please help - I can get it running but it's terrible occasionally backfiring and occasionally needs choking for a second to keep it idling.

Your help will be greatly appreciated.

P.S. if you live near Thornville OH - I would gladly pay you to come adjust this girl.

Thanks,

Chris Hibbert

The top screw is the low speed setting. turn this one in until it lightly seats in. Then turn it out about 1-1� turns. The lower one is the power screw or high speed setting. Turn this one in the same as the upper one and back it out about two turns. This will get your DC running good enough so you can warm it up good. After you have it running at or about operating temperature run the engine at full speed. Then turn the lower screw in slowly until engine cuts out or starts to run rough.Then slowly turn back out until it smooths out. That should take care of that one. Now set throttle at an idle. If it runs too rough to idle just speed it up a little. Now turn this one out,instead of in,slowly until the engine runs rough or cuts out. Then turn it back in until it smooths out. That should do it. If you have any trouble let us know. Good luck.

I did everything you said but the tractor would almost start but not quite so I choked it about 80% and it would start - I kinda went through the motions you described as if it were running right without the choke and noticed a slight difference when I screwed the top out. Still thouugh, I decided to try it out even though I had it choked almost full and drove it out in the yard. It does ok but falls on its face when under load - I did a compression test today and all four showed 118-120 although I did not do a bleed down test as I don't have that tool. What would be causing me to need almost full choke? Is that a sign of too much air coming in or not enough - could my problem be timing? I have replaced spark plugs and wires - the distributor cap looks new and so do the points and condensor. I know my battery is quite low - could that have something to do with it? Is the battery required once the tractor is running (forgive my ignorance) - perhaps that's my only problem - would a crappy battery cause you to not have enough power? Thanks for your help.

Chris