Help w/ my super A

I had not started my Super A for at least a year. After draining gas, soaking/cleaning the carb with carb cleaner etc... I now have gotten it started. I am not a mechanic....just a "parts replacer" so this was a big achievement for me.

It has a zenith carburetor with a idle screw at the top and a screw at the bottom of the carb (facing front of tractor). I have tweaked these but it will only idle. I took the carb apart again and shot cleaner through all jets (everything is clear). Now it starts fine but will not rev up. When I push the throttle up all the way, it moves the throttle but revs very little. As soon as I put it into gear it bogs down and will die if I don't push in on clutch. Afterward the tractor will sit and barely putt..... eventually it will build back up speed.

It is obviously not getting enough gas, but the line is clear to the carb, and the bottom of the carb is full of gas when I take it off and all jets are clear when I push carb cleaner through them. I am at the end of my limited knowledge and any help would be appreciated. Thanks

Fire it up and then grab the linkage rod going to the throttle plate of the carb and see if you can bring the RPM up that way. If you can then also make sure the gov tries to slow it back down if set at an idle. If those two things work check the linkage from the throttle lever to the gov and make sure it is moving a i should and that there are no broken springs. Could be as simpe as a bad spring or linkage binding some place

Thanks. I tried that. I even took the carb off and made sure the butterfly opened and closed all the way when the throttle linkage was moved. The RPMs will increase just slightly.....most times. When running the rod from the governor does move back and forth to regulate but no matter how much I open (or close)the needle on the carb, I can not get the RPMs up enough to run the mower. Any other thoughts, or should I try to figure out how to adjust the carb better? Any ideas on how many turns out the the idle screw or larger screw at the bottom should be to run accurate? Thank you for your help!

On the bottom of the carb there is a drain plug. With the engine off, the fuel valve on, pull the plug and catch the flow in a clean glass. It should full flow until the bowl empties out, then slow to a trickle. If the flow stops or slows to a drip, there is a fuel delivery problem to the carb. Could be the float is set too low, the float is binding, the needle is binding in the seat, or there is a restriction of the incoming fuel. There may be a screen in the fitting where the fuel line goes on the carb.

Look at the fuel that drained. Look for signs of water settling to the bottom, rust flakes, or dirt contamination. If it's in the glass, it's also in the carb and tank...

The adjustment screw on the bottom is the main (high speed) mixture adjustment. It should be screwed in to (gently) stop, then backed out 4 to 5 turns. Backing out enriches the mix. When it's right, the engine should take sudden throttle from idle with no hesitation. A puff of black smoke is normal, continued black smoke is too rich.

The adjustment screw on top is the idle mix screw. Start about 1 1/2 turns from seat. Turning it in enriches the idle mix. Adjust it to best idle with a warm engine.

A good diagnostic tool is to try a partial choke if lean fuel is suspected. If choking improves the running, it's too lean. If no improvement, there is another problem.

You could also have an ignition problem. That probably had a magneto ignition. Check the point gap and be sure they are clean. If you do find a weak spark, check the coil, cap, rotor, wires, etc.

Idle screw is just hat and only effect the engine at an idle. The lower screw is the main and you should be able to open it up to the point you get black smoke out of the exhaust. I you can not do that then the main jet circuit in the carb is still clogged up. You need to ruin a wire into all passage ways when you clean a carb. I my self use a torch tip cleaner tool to do that