Oliver 550 engine problem

If not, replace the ignition coil.

Just a thought.

How and who rebuilt the carb, did you pull the sediment bowl off the bottom of the gas tank and throughly clean it up? stuff like that.

I think we can get you going but it sometime helps to hear just a little more of something and some detail with it.

The problem you described sounds like what happens when I have my tractor idling and I shut off the fuel at the sediment bowl. The tractor runs for a couple of minutes then sputters, revs some and then dies out from lack of gas.

Also, all the coils sold by NAPA are marked as I previously stated... there is no "standard off-the-shelf" coil.

AS it's 12 volts, there are two alternatives really.

One is basically a '6 volt' or 'ballast resistor coil' with a ballast resistor in the circuit. The ballast resistor is to soak up, say, 6 volts (or there abouts) so there is (about)6 to 8 volts on the coil and 6 volts on the resistor when running. So they will be in series connection. When starting (and battery volts are being pulled down by the starter) the ballast resistor is short circuited (bypassed) so the full battery voltage goes across the coil and you get a better starting spark. As soon as the starter stops, the short circuit is broken and it reverts to feeding via the resistor.

The other option is a simple 12 volt coil with no ballast resistor and this one is designed to take the full 12 volts all the time and give a good enough spark at start up.

Modern spark ignition engines (before latest electronic systems) nearly always went for the ballast resistor type, due to smaller & cheaper battery, smaller & cheaper starter (slower cranking?) and longer life, cheaper coil (doesn't have to be built for extra starting energy).

So that is why a ballast resistor coil with no resistor is bad news. It will draw about twice the current (gives a super spark for starting), but inevitably will overheat itself and also burn the points (due to the high current at closure and high energy sparking at opening).

Follow coil supply wire back and see if it has two connections, one fed from the ignition switch, via the resistor, and one from the starter relay feed, to after the resistor.
A single feed from the ignition switch will generally indicate a simple 12 volt coil. Alternatively, disconnect the power lead at the starter, and then check the volts, across the coil supply and earth, with the key in 'run' position and then 'start' position, making sure the points are closed for the test. No change means simple coil; higher reading on 'start' position indicates there is a ballast resistor fitted.
Hope this helps.
Regards, RAB

Get a coil at NAPA that says "for use WITHOUT an external resistor". Get a new set of ventilated points while you're there. Run a #10 wire from the "+" side of the coil to the "I" terminal of the ignition switch. Remove any other wire from the "+" side of the coil but leave any other wire that's connected to the "I" terminal of the ignition switch. This will bypass any shunt.

This is exactly what I did to my 1650G when the shunt burned in my harness. I took the opportunity to rewire the entire tractor but you certainly don't have to. That was 5-6 years ago and the same points and coil are still in it.

You may want to look for the "I&T" Shop Service manual. Don't know if one is available for your tractor but the one for mine has excellent wiring diagrams in it.