rick rhea

New User
I have a 46 2n and I have no spark.Tractor ran good prior to sitting a few months? I have been many places looking for why no spark and have not figured it out yet.I have meticulously went through troubleshooting with an ohm meter and all checks out good.I have replaced the points and set correct gap .015. I hav e set the correct dwell.I have replaced condensor. I have checked resistance on the coil.I have replaced spark plugs and gapped them at .028.

I have4 2 major questions.
There is quite a space between the rotor and the distributor cap at where the plugs plug in? Is that correct? and while turning the emgine over my voltage at the distributor drops from 12 v to 8.5? Is either of thewe a clue to my problen and how do I solve it? Thanks for the help. Rick
 
" quite a space "

How much? 1/16" is common; a bit more is ok.

" I hav e set the correct dwell."

Do you mean timing?

" and while turning the emgine over my voltage at the distributor drops from 12 v to 8.5?"

That's the way it should be.

First, charge the battery. You need a strong battery to:

1. Close the solenoid

2. Spin the starter

3. Engage the bendix

4. Provide voltage to the coil.

As the battery gets weaker, the first thing to fail is your spark. If the battery is almost totally dead, all you will hear is the solenoid clicking.

The more current you use to spin the starter, the less you have for the ignition.

Before you check anything else, make sure you have the correct voltage at the top of the coil. It should be battery voltage w/ the points open & about half that w/ the points closed.

Assuming that the bushings & advance weights are ok, & that you have correct voltage to the coil, the most common electrical failure (no spark, weak spark) points on the frontmount are:

1. The insulator under the brass concave head screw & where the copper strip attaches. (it’s fiber & will wear out; poke & prod w/ your meter leads to make sure it still works)

2. The pigtail at the bottom of the coil not making contact w/ the concave head brass screw inside the distributor. (With the coil on, the pigtail must firmly contact the brass screw. No contact = no spark.).

3. The copper strip is broken or grounded to the plate. (look very carefully for cracks & breaks)

4. The condenser wire grounding to the plate or side of the distributor.

5. The tab on the bottom of the coil not making contact w/ the brass button on the cap. (With the cap on, the tab must firmly contact the brass button. No contact = no spark.)

6. Incorrect positioning of the spring clip on the plate causing the pigtail to ground. (the open part of the clip goes between 7 & 9 o’clock on the plate. That puts the straight part of the clip opposite of the timing screw at 3 o’clock)

7. Incorrect seating of the coil on the distributor due to a loose bail or no gasket.(the coil must not move at all; if it does, replace the gasket or bail. Or stick some cardboard under the bail).

8. Water/moisture inside the cap due to gasket failure or the absence of a gasket. (the cap AND coil have gaskets)

9. Dirty/corroded/burned/incorrectly gapped or misaligned points.

10. Burned rotor, cracked/carbon tracked cap.

Unless the coil is cracked or shows a dead short, chances are it's fine; square coils rarely fail cold. Pull the distributor & do a continuity check.

First, make sure your meter/light works (don't ask....)

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.

Inspect the points; if they are pitted or burned, replace them. Next, dress the points by running a piece of card stock or brown paper bag through them. New points sometimes have an anti-corrosive dielectric coating on them & old points can corrode or pick up grease from a dirty feeler gauge or excessive cam lubricant. Make sure the points align correctly. Proper alignment is also critical to longevity. Look at the points when they are closed; both sides should mate evenly. Then, check the gap at .015 on the high point of all 4 cam lobes.

Now, 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. Coil on, 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!

At this point, I just put the distributor, coil & cap all back on the tractor as a unit. The reason I do this is because it is real easy to get the cap or coil mis-aligned trying to put it back together one piece at a time & the result is something gets broken or you get a ‘no spark’ problem.

It's possible to put it back on wrong & break it. 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.

Finally, double check your firing order & plug wires. It’s 1-2-4-3, counterclockwise. It’s very easy to cross 3 & 4.

Post back w/ results & any other questions.
75 Tips
 
Rick.......you report......"There is quite a space between the rotor and the distributor cap at where the plugs plug in".......uh? that cap button inside the crab-cap should be "spring loaded" so it touches the rotating rotor. Time for a NEW CAP iff'n the spring loaded button is missing ........Dell, yer self-appointed sparkie-meister
 
" the distributor cap at where the plugs plug in""

I think he's talking about the end of the rotor & the cap nipples......

But maybe not.
 
I think that I am talking about the end of rotor and the inside of cap (maybe called cap nipples) it is oppisite where the plug wires plug in. I thought that the rotor was supposed to actually touch the cap at each plug spot but it appears to be about 1/8 or so from touching?
 
(quoted from post at 12:20:34 06/21/13) I think that I am talking about the end of rotor and the inside of cap (maybe called cap nipples) it is oppisite where the plug wires plug in. I thought that the rotor was supposed to actually touch the cap at each plug spot but it appears to be about 1/8 or so from touching?

If the rotor touches the cap while spinning at 1500 rpm, your gonna do lots of damage to the cap and button...probably more.

The gap you are talking about is supposed to be there. Spark will jump from the button tip to the cap contact as it rotates past, thus sending spark to your plugs.

Nipples are where your plugs connect on the outside of the cap. And yes they are "opposite" (inside vs. outside of cap) of each contact inside the cap.

Do as Dell said and make sure the spring tab on top of the button actually touches the coil contact on the inside center of the cap.

Man...this is getting confusing :lol: :lol:
 
Thanks for the reply. This thing is driving me nuts. I will check the spring tab on the rotor.
What about the 12 volts at the top of the coil and then with turning it over the voltage drops to 8.5 volts?
 
" What about the 12 volts at the top of the coil and then with turning it over the voltage drops to 8.5 volts? "

I've already answered that question once.

Are you getting my posts or did you overlook the answer?
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