2n wont start

Hi everyone...new to the site was directed here by CLTX. I have a 40 something 2n, 6volt. Blew the head gasket between cylinders, replaced the gasket and rebuilt the carb that was full of anti freeze. Checked points, new plugs, etc. have spark and fuel....but it won't start just coughs . Firing order is correct. Last time I changed head gasket I had to pull start it and it fired right up. I think the starter may be dragging and pulling too many amps to let it start, next rebuild. Any ideas why she won't start. Forgot all of the tricks to working with a point system.

There are ways to check for spark & fuel that work & ways that don't. For example, having gas to the carb is nice, but having it past the float is what counts! That’s why removing the bolt in the bottom of the carb is the way to do it. And, same thing w/ spark at the plugs. Some folks think that checking for spark means pulling a plug wire off & looking for one. Well, it's the distance the spark jumps at the plug that gives you the info you want. It takes about 17kv to jump a 3/16" gap & 22kv to jump ¼” in the open air, so that's why you need to use a spark plug. Or, a store bought plug checker. Remember, it’s 14psi outside of the engine & about 90psi at a 6:1 compression ratio in the cylinders & compressed air crates electrical resistance, so you really need the 17-22kv to fire the plugs when the engine is running.

Before you try anything else, see tip # 43 for the safe way to jump it. If the starter is dragging or you have a compression problem, the faster cranking of the 12v will help.

If that doesn't work, time do a continuity check in the distributor.

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.

2. The insulator at the end of the points where the copper strip attaches.

3. The copper strip is broken or grounded to the plate.

4. The condenser wire grounding.

5. The pigtail/tab not making contact.

6. Incorrect positioning of the spring clip on the plate causing the pigtail to ground.

7. Incorrect seating of the coil on the distributor due to a loose bail or no gasket; the coil must not move at all.

8. Water/moisture inside the cap due to gasket failure or the absence of a gasket.

9. Dirty/corroded/incorrectly gapped 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....)

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. Then, check the gap at .015 on all 4 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 (it’s easier to do this from the left side). 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.

Post back w/ results & any other questions.
50 Tips

Thanks, checked all of that, been reading this forum for awhile. Spark plug jumps a good spark, orange though not blue as often mentioned. Just did the distributor not too long ago and used the information I found here to help, it was running and starting good until the gasket went.

Oh forgot to mention. Tried the 12 volt jump to the starter, it did not spin any faster therefore I think I have starter issues.

Pull the starter out from the block & clean it all up. Might just be a ground issue. (see tip # 36 before you do that)

50 Tips

Thanks Bruce....look like I have a lot of things to check this weekend if the snow stops and I can work on it.