IH 2400b backfire out carb- surges

Greetings
I have a IH 2400b that was running fine the out of the blue started surging badly, luck to make it back to the shed
After checking and cleaning carb , pulling valve cover looking for valve train issues, - all looks ok
I m stumped
How do I know if I have a timing issue or something else going on?
Any help is appreciated
Thanks

As long as the point gap is correct timing doesn't just jump out of place on tractors. Back fire out of the carb most of the time is a lean condition. Does choking it help??

Check the points condition and gap. Check the distributor shaft for side
play, if loose the points will not stay set and cause strange symptoms.
Also be sure the centrifugal advance is free and working, the rotor
should turn a few degrees and spring back when released.

Look the rest of the ignition system over, each plug wire should give a
minimum 1/4 inch spark to ground at the plug end of the wire. Wet wires,
bad wires, or water inside the cap, carbon tracking can cause misfire and
backfiring. How do the plugs look? If any doubt, replace them just to say
you did.

If all that checks out, revisit the carb. Be sure you have sufficient
fuel flow through the carb. With the fuel valve open, have a clean glass
ready, remove the drain plug, catch the flow in the glass. If there is a
fuel pump, do the test with the engine running. The flow should remain a
steady flow, not slow to a drip or stop. Look at what was caught, look
for water and contamination. If the fuel is contaminated the tank will
need to be removed and cleaned. If flaking rust, it may be time for a new
tank. Fighting a rusty, dirty tank will bring continuing problems. Inline
filters do not play well with gravity fuel systems.

If the main jet is adjustable, try opening it some. If a fixed jet, did
you clean it with a stiff wire? Spraying and blowing can look clean but
leave residue still inside the jet, just enough to lean everything out.

Sounds like the carb is not getting gas to me. Steves
check list would get to this but just in case you do not
know the elbow the fuel line hooks to on the carb has a
screen on it. If you never pulled it out it may very well
be plugged. Your machine may be a little different but
generally in original form the main fuel screen or filter
is in the top of the sediment bowl under the fuel tank. I
also see your tractor may have a fuel pump so that
could also be an issue.

Condenser??

Rare for a condenser to go bad unless it was just replaced

Choke in any position makes no difference

Condenser was replaced about 6 weeks ago

Plugs cap rotor wires condenser points coil are all 6 weeks old.
I have good spark
From line at carb and cranking engine for 10
Seconds I get a little better than a trickle of fuel
Hard to see with out an assistant
Probably 2-3 ish ounces
Is there a volume spec for this amount?

Sediment bowl is clean

In that case it could be the problem. Put the old one back in

Try disconnecting the output of the fuel pump, direct it to a container.

Crank the engine and watch the flow, it should give a full, strong, pulse of fuel each time the pump cycles. If not, be sure there is unrestricted fuel available for the pump, no air leaks in the suction lines. Typically a pump will make about 3 PSI and should hold pressure with your thumb over the hose.

Is there a screen in the carb inlet elbow fitting?

If it has a fuel pump it should shoot gas out of the line at the carb if taken off a good 3-4 inches

Ok

Rechecked fuel lines at pump and carb

No screen found

No leaks sucking air

Went back to the distributor and removed went over all
connections and weights and spring move freely

Started tractor and no more surg

With gov rod on carb it runs away- revs very high-no idle
adjustment with throttle lever

Also found 1st rover only hitting slight edge of the valve

Thought this was odd- pic

Ok

Rechecked fuel lines at pump and carb

No screen found

No leaks sucking air

Went back to the distributor and removed went over all
connections and weights and spring move freely

Started tractor and no more surg

With gov rod on carb it runs away- revs very high-no idle
adjustment with throttle lever

Also found 1st rover only hitting slight edge of the valve

Thought this was odd- pic

Good chance you have a BAD head gasket. One thing to try is pull the dip stick while it is running and see if you get air/oil out of the dip stick hole

Sorry wrong post