1948 Front Mount Distributer Timing for Dummies?!?!

First let's start off with I own and HAVE the Ford IT FO-4 Manual. Extremely helpful. But only being 35, and living a somewhat sheltered life growing up have not had the fun of doing tuneups on older cars or in this case a tractor.

I bought all the parts and was able to easily remove and reinstall NO LEFT OVER PARTS. But, I fail to understand exactly what is meant by contact point gap is 0.015 air gap.

It says make sure the contact points are parallel when closed. But makes no mention of exactly how to do this. Where any sort of adjustment is or how you need to assemble it to ensure this happens.

"Rotate the distributor cam until the rubbing block of the breaker arm is positioned at a high point of the cam." Ok obviously the distributor cam is the nice keyed piece in the center that the rotor will fit on. I got that. Now when I rotate it is the high point where the rubbing block is closest to the cam and then I adjust the eccentric screw to ensure the air gap at the two points it 0.015 gap with the feeler gauge at that point?

Next step timing to engine. Now the introduce a term but don't call it out anywhere that I see. "Tang" having drank this as a kid, and having looked in the dictionary this word seems to be possibly not used right, but I'm going to go by the Illustration and assume that the tang is the piece that spins again this time with two metal blocks on top. Place a ruler so it lines up 1/4 inch from the small hole nearest the timing plate and a quarter inch from the top hole.

Now I need help with understanding what it means by adjustment plate on the left side of the distributor. Then how do you know proper timing is obtained? It mentions to turn shaft backward 1/2 turn to eliminate backlash then repeat the check? Can someone please try and simplify this or put it into something maybe a first grader could do? I'm failing to understand this.

Do as JMOR suggest. However, if you purchased a set of points manufactured by TISCO the chances are your tractor will start running poorly and may even not run at all after several hours of run time. TISCO front mount points are junk. They are what is normally sold by Tractor Supply and some AG stores. Try to find Blue Streak point made by Standard Ignition. NAPA may carry them or this site may have them. There may be other brands that work well also but Blue Streak is the only one I have found that will hold up.

From what I"ve seen, ALL TISCO parts are JUNK.

Thank you both! I THINK I understand it better now. Out of curiosity if the points are setup wrong, what is the likelihood that I will receive no spark?

I would not mess with the timing. Get your points set right and I bet it will run..Lots of folks make a big deal out of setting the timing every time you turn around..IT AIN'T necessary. My Dad has had a 2N for 45 yrs and the timing has never been touched..It cranks immediately and has the power it is suppose to have.

It depends on how "wrong".

A gap of .010 or .020 will get you a spark; the wider or narrower you get results in no/weak spark.
50 Tips

You can change points everyday & it will not fix bad bushings. If you are having trouble w/ points failure, check the shaft. If you detect movement, chances are it needs new bushings.



The next trick to points lasting a long, long time is annual maintenance. (tip # 40) No matter how well it's running, pull the distributor check the gap & put a dab of points lube on the cam. Not bearing grease or Vaseline; use the correct lube.

Quality parts are critical to longevity. Having learned the hard way, I most always use Blue Streak brand points. They are made by Standard parts & available at many auto parts stores. (frontmount points also fit a 48 Ford as I recall) Beware of sticker shock: $16-18 a set. My next choices are Wells or Echlin. Look for a brown rubbing block. Unfortunately, many folks have experienced problems w/ points made by Tisco, Sparex, A&I Products and any TSC ignition parts..

Correct points installation & gap is also important. Make sure the blade is at a perfect right angle to the points & you want to feel just the slightest bit of drag when you pull the blade through the points. Make sure the blade is clean & that you dress the new points by running some card stock or a piece of brown paper bag through them. Gap is .015 on the frontmount on all four lobes of the cam. Make sure the points align correctly.

Even as tight as I am, I always change the condenser when I change the points…….and then I toss the condenser in the “used” parts box. A bad condenser is rare; you can tell if the points are pitted/burned w/ metal transfer.

Good hold-down screws are important. (tip # 37) If the heads are wallowed out, what do you think the threads look like? You can use machine screws as temporary replacements, but you should use the OEM Fillister head screws. The larger head is there for a reason. If you do use standard machine screws, make sure they aren’t too long & interfere w/ the advance weights. Always use star washers under the screws.


When I was 16 years old making $1.25 an hour & a set of points cost $1, I filed points. I must have been good at it because I recall it was almost a weekly exercise. If you ever file a set of points, you will remove the metallic coating on them & reduce the life span considerably. Unless you plan to keep on filing them, plan on replacing them pretty soon!

It does not matter if it’s 6 volt or 12 volt, you must use the OEM ballast resistor on a frontmount. Too much current to the points will burn them up in short order (leave the key on with the points closed & you will experience this “learning point” in about 3 minutes, tip # 38) For a 12v conversion on a frontmount, you probably need another resistor in the circuit as well but unless you measure the coil resistance, you will not know for sure.

Timing is important to engine performance. Make sure you set the point gap before you set the timing. Get a meter or test light, a 21/64” drill bit & a metal straight edge. Put the distributor face down w/ the condenser on the left & the timing plate lock screw on the bottom. Look at the end of the shaft: it has a narrow side & a wide side. Make sure you can tell the difference. Now, place the drill bit in the bottom mounting hole. (this will be your reference point for measuring) . Next, place a straight edge on the wide side of the tang on shaft as shown in fig. FO83 in the I&T FO4 manual. Rotate the shaft CCW (as viewed from rotor side OR CW as viewed from back/tang side) until the straight edge is ¼" beyond the outside edge of the drill bit you stuck in the distributor mounting hole. At this distance, the distributor points should start to open. (get your meter/light out now & check) If not, loosen the timing plate lock screw and turn to advance or retard the timing. (move the plate down to advance timing, up to retard) Remember, each one of those little hash marks represents about 4* of timing. Keep adjusting until you get the proper ¼" setting. (if the plate won’t move, you might need to remove the big C clip to loosen it a bit) As you’re adjusting, eliminate backlash by turning the shaft backwards (CW as viewed from the front) and bring the shaft forwards (CCW as viewed from the front) to measure your setting. This ¼" setting will get you static timing at top dead center.

After you set the points & timing, do a continuity check before you put the distributor back on the tractor. Before you start, make sure your meter/light works (don't ask....)

With the distributor still off the tractor, 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!

4. Coil on, cap off, points open. One probe on the lead on the top of the coil, the other anywhere on the body of the distributor. You should have no continuity!

Look at the slot on the end of the cam shaft. What ever angle it happens to be, turn the distributor tang to match it. Make sure you can tell the wide side from the narrow side on both the cam & distributor! (close counts)

Then place the distributor on the front of the engine, gently push it in place & slowly turn the distributor body until you feel the tang slip into the slot. Rotate the distributor body until the bolt holes line up. Then, hand tighten the two bolts until the distributor body is flush w/ the timing gear cover.



Hopefully between this info & what JMOR said, you will be able to set the points & timing. If not, post back w/ any other questions.

50 Tips