Backfiring and not running without choke almost closed

[T. Highway]

You may want to look at the base gasket, there are three that are close but they don't allow vacuum to the accelerator pump properly. This would be a simple fix.

Here is a link to the different gaskets: http://www.g741.org/PHPBB/viewtopic.php?f=3&t=5348&p=41869&hilit=Carb+base+gasket#p41869

Bert

 

[grimlock97]

thanks for the link, my base gasket looks identical to #2, my gasket kit was a NOS kit from ABLINN, I made sure it did not block anything on the bottom of the carb before installing it.

 

[trukhead]

I feel your pain. Old tractors go afoul quickly with today's fuel. It sounds to me like you have a carb problem. But first deal with the ignition and get it dialed in as close as you can statically. Get the timing close, adjust the dwell as close as you can via the point gap.
Now onto the fuel delivery. Make sure the fuel pump is pumping to the carb correctly and not leaking in to the crank case and delivering the proper amount of fuel in a given time frame of cranking the engine over and running the fuel flow into a container so you can measure the volume of fuel delivered.
Now onto the carburetor. You have a plugged passage some where. There are air bleed circuits, air bypass circuits, fuel circuits and who knows what else in the mysterious carburetor.
I recommend you get a WYPO blue covered torch tip cleaner.
You can dip the carb body in carb cleaner and that gets most of the body clean.
I have found that I must them take the WYPO cleaner out and probe all the passages. I have found that some passages just don't get clean. I them use spray carb cleaner with the flexible hose tip and start the process of spraying the passages to see where the spray comes out. sometimes spray comes out in one place, sometimes two places and even 3 places.
After all of that I them dunk the cleaned carb body in the parts cleaner with nice clean parts cleaning fluid just to get the carb dunk stuff of but also to alow me to se where the air nozzle with push air through the newly cleaned passages. With the carb body clean and dry I know will examine it for holes (passages) and poke each one again to see how far the smallest and then the next largest cleaning wire will go and see if the depth is logical.
What I mean by logical is, does the passage intersect with a drilled boss or another drilled passage. It is after all this effort that I have found that last plugged passage that had caused the carb to not operate correctly and addressing that last passage and turning the carb into a successful, tunable carburetor.
You can now tune the carburetor to close settings to now allow you to go back to the ignition and really dial the ignition in and then come back to the carburator and get that fine tune.
good luck!