Carburetor Adjustment?

OK guys, here's another one.

While I'm still trying to find my Max Engine RPM setting, and where to mark my new throttle quadrant to show me where to run for my 540 RPM PTO speed, I actually had some work to do with the tractor.

I have just replaced the Chinese carb that was on the tractor, (and that I could never get to run right), with an original MS unit that I just rebuilt.

I had some not-too-serious grading to do that included an uphill section. When I first started the tractor coughed and sputtered, so I kept adjusting the main-jet needle until she was running pretty good.

When I got back to the garage and shut down, I counted the turns back to closed. I was out THREE FULL turns, (and had virtually no tension on the spring)

Any thoughts on what's up?

As always, thanks in advance for any advice.

Jim

Make sure the tractor is at operating temp; that usually takes 10 15 minutes at idle depending on ambient temp.

Both Ford and Marvel/Schebler (assuming you have a M/S carb ) say to set both the side-pointing idlemix and the down-pointing mainjet to 1-turn as a starting point. I set the down-pointing mainjet to 1-1/2 turns and don't fool w/ it until the final step.

Then adjust the side-pointing idlemix for fastest idle; not the smoothest idle. Next, adjust the behind the carb idle-speed set-screw for very slow 400-rpms idle. Do that idlemix adjust for maximum idle at least 3-times. Make sure that you turn the screws slowly, like 1/8 of a turn at a time & wait a second or two for the engine to catch up. Take your time!

Do it like this:

1. Adjust idle mix jet until RPM increases

2. Adjust idle-mix set screw until the engine nearly stops (as slow as you can get it unless you have a tach that tells you 400 rpm)

Repeat steps 1 - 3 three times.

Remember the side-pointing idlemix is out for lean, in for rich.

If you do not have any problems inside the carb, it is easy to get the idle down to 350 - 400 rpms.

Your last step is to go back to the main jet. Remember, in for lean, out for rich. If you end up turning it OUT more than turn for max power (remember, you already had it 1 turns out) then stop right there because you have a dirty carb or a fuel problem.

Lastly, each of us has his own definition of a carb rebuild. If your rebuild did not include soaking the carb 24 hrs in a bucket of caustic carb cleaner & blowing out every orifice w/ a rubber tipped air gun, you didn't do a rebuild, IMHO. You just replaced parts.
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Thanks Bruce. I DID soak the old carb that I bought in a bucket of Berrymans Carb Cleaner, but only overnight, and it was a COLD night. (Not sure what Berrymans IS... but it doesn't smell anything (strong) like the carburetor cleaners that I remember from back-in-the-day. It COULD be that it is now Environmentally Sensitive, and therefore worthless.) I'll try again, and this time I'll bring the bucket into the house where it will be some warmer.

Yea, that stuff was strong smelling. Last time I needed some, it was out of stock, so I ended up w/ NAPA carb cleaner.

Anyway.........

If you have it open 3 turns, you've got something clogged.

Did you get wire though all the jets?

Tnx to JMOR, this is the best carb cleaning post out there. https://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=nboard&th=767359
75 Tips