No power

I have a 544G international tractor that I am trying to tune up. I have installed new plugs, points, condenser rotor cap and installed a kit in the card ( marvel-schebler) the carb was gummed up. The carb was missing an jet-economizer which caused it to run to rich. I ordered and installed the jet now the engine will start and idle good and will come up to speed but when you have it in gear and let the clutch out there is no power and the engine will die. Any ideas where to look next, thanks

Sounds like it may be too lean.

If there was no economizer valve, there probably never was one, and the port was never drilled for it. I've never actually seen one with the economized valve, only pictures. I don't think it will hurt to leave it in, probably will make no difference.

First, be sure the distributor is in good working order, there should be minimal side play in the shaft bushing, and the centrifugal advance is free and working. Was the timing changed? Reasonably sure it is correct?

Is there a good, blue hot spark at the plugs? It should be able to jump 1/4" at each plug. If not, revisit the points, condenser, wires, and possibly coil.

How is the air cleaner? If that has an oil bath cleaner, there is a wire mesh element above the oil container. It is often overlooked, could be plugged.

Is there good fuel flow to the carb? There is a drain plug in the carb bowl, with the engine off, fuel valve on, remove the plug, catch the gas in a clean glass. The flow should start strong, then reduce as the bowl empties, but still continue to trickle. If it stopps or slows to a drip, there is a fuel delivery problem. Look at what was caught in the glass, if contaminated, the tank will need to be cleaned out. The contamination will also be in the carb. Even though it was cleaned, if the fuel supply is contaminated, it will need to come back apart and rinsed out.

Once everything is checked, the air cleaner is connected, the choke open, engine up to temperature, let's adjust the main jet.

Set the engine for full governed speed. If it won't take full speed, open the main jet until it will. Take hold of the governor linkage and push the throttle closed. With the engine held at idle, release the governor, the throttle should go wide open until the engine is up to speed. Listen to the engine while it is coming up to speed. If it hesitated or dies, open the main jet 1/4 turn, try again. Keep doing the test, opening the main jet 1/4 turn at a time until the engine will accelerate without hesitation. A single puff of black smoke is what you want to see.

Let us know...

this carb only has one external adjustment and it is called air mixer valve on the diagram currently I have it about three quarters of a turn out is this the adjustment you are talking about, thanks

You didn't say if it ran good or not before the tune-up. Is the timing correct? Late timing will cause this problem.

This is what I'm used to seeing.

The small screw up by the flange is the idle mixture, turn in to richen, out to lean.

The large knurled screw is the main, turn in to lean, out to rich.

Is yours like this?
Marvel Schebler

the carb I have only has one external adjustment listed as a neddle (idle adjustment) screw part number 5 on my diagram. I believe that it is a model B type with a anti diesel selonoid at the bottom I incorrectly called that external needle a air mixture needle in the last message sent to you. The tractor did not run at all before I began working on it and had set for a while for unknown reasons to me. I cleaned out the fuel system and put new plugs in it along with points new rotor cap and wires also condenser. The motor started right up and will idle fine but there is no power to pull itself. I have run over five gallons of fuel thru the engine trying to set the carb but it is running very rich. I did a compression test to see if that was the problem with all cylinders from 140 to 130 psi and noticed that the plugs were very soot covered that is when I discovered the economizer jet missing putting the jet in helped but did not allow the engine to produce enough power to pull in second gear which would be required to mow with a brush hog. I believe that the distributor is functioning and had moved it to see if that would help with the power each time moving it back to the original position. I am not sure what the proper setting is for the advance but in my experiments the original setting works best. I would send a picture of the carb diagram but am unable to upload to this email, hope this helps thanks in advance

Did you forget to put the venturie back in ?

(quoted from post at 05:59:17 06/06/17) Did you forget to put the venturie back in ?

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did put the Venturi back in but I dosent look like the one in the picture of the diagram sent to me. How much would that change the flow of fuel in the carb

Will it fit upside down?

(quoted from post at 10:55:22 06/06/17) Will it fit upside down?

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Not if it's a Marvel-Schebler, it won't. I just went through mine.

Please try to get the pic uploader to work, makes things a lot easier.

Nobody has mentioned a critical first test: does this engine have good compression? if not we're wasting time fiddling with carbs and points and such. Another often-overlooked problem is plugged exhaust--does your rainflap open? But it should be easy to diagnose a plugged air cleaner, take it off and see if the motor runs better.

I did a cylinder check before the tune up the pressures were between 140 to 130. The carb had home made gaskets in it and the Venturi was very worn ( thin with chips out of the top ) I have decided that I need to change carbs and am going to a different brand which is yet to be determined recommendations would be appreciated, thanks

My guess is that you won't have a lot of choices, Marvel-Schebler or Zenith. "Homemade gaskets" in a carb, even one as simple as this, scares me! Kits are available. I recommend you get a service manual before tackling it unless you're a carb guru, though, especially if some butcher has been there before you.

If it is a M/S carb most any part you need for it can be had. Shoot this site sells a lot of stuff for carbs. Nice thing is with a M/S is that there are 4 sizes small medium large and extra large And most parts will interchange form each size.

Good call teddy. I bought a 574 and the venturi was upside down causing the same issues.

Did it run OK before? Is the governor working properly? Is the distributor
advance free and working properly?