The FORD Front Mount Distributor is the most misunderstood feature on these old FORDs. Many other features are required as well. The Front Mount also requires the OEM Ballast Resistor in the coil circuit in both OEM 6V/POS GRN and a 12V conversion. Distributor settings are as stated in manuals. The entire wiring system must also be right. As JMOR said, the design was the Camshaft Head had an offset Female slot on it and the Distributor Cam & Weights had the offset mating Male Tang. Both parts must be fitted exactly right to function properly. Don't assume your rotor direction is going to be right; there is more to it than that. Timing is done on your bench a certain way and uses no timing light. Gotta have the manuals to see how to do a proper tune-up. After assembly and bench testing, mounting the unit becomes the crucial point. If you force the unit down to the engine surface 180 DEG off, it will bust the aluminum base at first power up and render it junk. You'll then need a new or good used base to replace it with but the guts are still good so can be swapped out. Retesting is required. Use a good Mini-Mag and a hand held telescoping Inspection Mirror to orientate each part for mating. There is a paper gasket on the distributor base to engine surface. Be sure old material gets removed before applying the new one. Ditto for the ROUND CORK gasket that fits over the CAP to the distributor face. Always use your hands to 'feel' for fit and function. Two 5/16 hex bolts fasten the unit to engine. Hold unit flush and insert start bolts observing unit is flush and not kinked to a side. Hand tight and one more look to be sure. Always use your Essential Manuals and don't try to align the rotor just eye. Take your old distributor and look to see if you have had it off and you got it wrong and it is now busted. Yes? You need a new base. No? Unit should be good. Check timing once more and test before mounting again. At a tune-up rebuild, you can do preliminary testing on the bench before mounting. Once unit is mounted correctly, more testing is done before you try to start engine.
Here is a good procedure that Bruce (VA) wrote several years ago for front mount settings.
With the distributor off the tractor on your bench, follow these steps:
1. Coil off, cap off, points open. One probe on the brass screw & the other on both sides of the open points. On the side closest to the cam, you should have continuity. Not on the other side! If you do, you will also have continuity everywhere because the points are grounded.
2. Coil off, cap off, points open. One probe on the brass screw & the other anywhere on the body of the distributor. You should have no continuity! Now, rotate the tang on the distributor....as the points open & close, you have continuity (closed) and lose it when they open.
3. Put the coil on the distributor, cap off, points open. One probe on the lead on the top of the coil, the other on the cam side of the open points. You should have continuity!
Once unit is mounted, further testing before start up is advised:
II. Testing for voltage at the Square-Can Coil & Distributor:
Using your VOM, set unit to VDC and measure battery voltage static, make note what it reads. Take one probe on the VOM, polarity doesn't matter for this test, and connect it to the LH terminal on the Ballast Resistor as viewed from behind the dash. There is only one wire at this connection and it is the coil wire to ignition switch. Take the other VOM Probe and place it on any metal ground point. Turn Ignition Key Switch to ON but do not turn over engine. Now press the Neutral Safety Start Pushbutton and observe engine cranks but should not start. Observe what the voltage reading is and note. Reading should be battery voltage as notated previously with points open, half that with points closed. You can test points opening and closing by bumping the Safety Start Pushbutton and holding down it will open and close itself. Test Fails, no readings? You have a wiring issue. Test Passes? You are getting voltage to the circuit at the resistor as it should. Move on to Coil. Repeat this test only place the probe from the Resistor to the top terminal connection post of the Coil. There is only one terminal connection on the square can coil. If test passes and you get a reading on your VOM, it indicates you are getting voltage to the coil as it should be and you can move on to the Spark Test. If it still won't start, the problem is in the distributor. You can first try to remove the coil only and test the pigtail spring to see if it sufficient to make electrical connection to the points. May need to gently pull on pigtail to stretch out for a better connection then replace the coil on the unit and try to start engine again. If still a NO-GO situation, you will need to get the distributor back on your bench review rebuild.
FRONT MOUNT DISTRIBUTOR:
Tim Daley (MI)
