Starting John Deere 420C (crawler)

[Bookman]

I have a 1958 John Deere 420C (crawler). It has been completely overhauled but it is hard to start. Usually I end up putting a battery charger on it and even using starter fluid. Today, I could not get it started even doing that. The temperature is in the 40s here. Any tricks I should know about it getting it started? Thanks in advance.

 

[CPeter]

How hard is it to turn over? I have a 420U with a 6V electrical system and It will start down to at least 0º F and maybe more. These are pretty simple and unless there is something wrong, they will usually start if they will turn over. What are you using for oil in the engine? Does it have an external hydraulic pump? What weight oil in the hydraulic system? Do you push in the clutch when trying to start it?

Mine likes just a short full choke and then it will run without any choke after a few seconds.

I assume that you have good spark and that it is timed right. In cold weather the timing is more important than at 40º (tropical here in New Hampshire). You can file a little bit off the end of the rotor to build the spark up just a bit more. New plugs (many different thoughts of the brand and number on this) are probably necessary. Points need to be good and set right. Condensers are a crap shoot. New ones can be worse than the old and if you have one that is good, don't replace it!

With some answers to the above questions, I may have some answers.
CPeter

 

[Bookman]

It is a six volt system and 30 weight oil in the engine. I do not know the weight of the oil in the hydraulic system. It has a blade on it. It turns over fine,
particularly with a battery charger on it, but just does not fire. Pushing in the clutch does nothing. I have not done anything with the timing since the overhaul. I
have not checked the spark or checked to make sure the gas was getting to the carb. I have tried the easy stuff so far....charger and starting fluid. Thanks

 

[Mogster]

It is cursed, if you give it to you will never agin be troubled by it. Lol check for spark.

 

[Bookman]

If you do not mind, I will check the spark, check the gas, check the oil, check the whatever....before I conclude it is cursed and give it away

 

[Aussie Ken]

I have a 420 Standard -all fuel engine -that needs work that I bought here in Australia.
The former owner had installed a 12 volt coil - the generator is not hooked up
I bought the tractor without a battery - but had received a video from the former owner showing it running quite well, but the carb needed work
When I got it shipped here -I connected a 6 volt battery --
I had a Hell of a time to get it to start and when it did - it popped and farted real bad
I rebuilt the all fuel carburettor - no better
Replaced all electrical ignition parts -- plugs, wires, points, condenser, rotor, cap -- no better
I removed the coil and cleaned the outside -there it was 12 volt ----
I installed an old 6 volt coil that I had purchased in a box of parts at an auction sale
The tractor started right up and ran pretty good
I still need to get new battery cables - the bigger the better - 2 aught - they are best for 6 volt systems

make sure you have a good strong spark - same voltage battery and coil and a great flow of fuel

 

[Resting Relics 1]

Hey Bookman,
This Dubugue series from M through the 430 are notorious for hard starting if the battery and starter are not in top condition as well as being timed and tuned up. Also as Aussie Ken says look at replacing the coil. I too found the wrong one on my old MC, which caused lousy starting as you describe. Good Luck!
John

 

[M-MAN]

Your third sentence along with clarification from a later post tells me you are losing too much voltage while the starter is engaged so there isn't enough left to fire the ignition. That's why it fired with the added volts from the charger. It takes 5 volts to fire reliably and you're not going to get that without PERFECT wiring, extra heavy cables, and clean shiny connections. That's one of the major problems with a 6v system. Everything must be in like new or better condition for them to crank. Too much trouble and expense for me. I prefer a reliable 12v system where it doesn't matter if you lose 1 & 1/2 volts while cranking. To each their own.

Lose the starting fluid. Dubuques don't need it and you'll do more harm than good. After you get the wiring and connections fixed/upgraded you can start on the current problem. You need a fresh set of points (possibly a condensor also) and two new Autolite 216 plugs. Get her running and put a timing light on her. SPARK should be centered in the timing window at full throttle. It woulden't hurt to make sure it's a 6v coil on there also. IF compression is decent, the ignition components are up to snuff and the carb is right it won't turn over but a couple times before she runs.

 

[CPeter]

(quoted from post at 23:32:22 12/28/16) Pushing in the clutch does nothing.

The reason I asked about the clutch is that by pushing in on the clutch, you reduce the load on the starter of the gear oil in the transmission. Thick oil in the engine, hydraulic system and transmission can add a lot to the starter load and slow down the speed at which the engine turns over. It would appear that you have a spark issue. Did you have the distributor out maybe get the plug wires on in the wrong position?
CPeter

 

[Bookman]

Yes, I think a spark issue too. It is turning over fine. thanks

 

[Bookman]

Thanks, I am more a Farmall man, and I have several 6 volt Farmalls. So, I understand about the need for everything to be in top shape for a 6 volt. Usually the first thing is a ground is bad, but I checked that yesterday and cleaned the battery cables. I put in fresh gas. Obviously I am not much of a mechanic, and I hate to start throwing parts at it until I get a better understanding of what is going on. Spark plugs are not much, and probably neither is a condenser. I probably should at least check the points and clean them a bit. I think the last time I started it was last February, in much colder weather than yesterday. Thanks much.

 

[Bookman]

Thanks much. I will check the coil. I doubt I have 75 hours on it since it was completely overhauled (bored out, new pistons, etc.) but that was about 10 years ago.

 

[Bookman]

Thanks, as I mentioned in another post, I am mostly a Farmall man with several 6 volt tractors. The first thing I have learned to check is the ground. I did that yesterday. Plus I do have heavy duty cables on it from the battery. It was completely overhauled about ten years ago by the local John Deere dealer. That includes boring out cylinders, new piston, etc. for $$$$. Now that does not mean they did everything right since the crawler is older than the mechanics there. It has always been hard starting, but I figured tight tolerances on a new overhaul. But yesterday I got nothing, and I had put in fresh gas. So, probably a spark problem somewhere. I will try the cheaper stuff first before I start throwing money at parts. It might be just the points are a bit corroded. It has been about 11 months since I started it last. Then I will look at new spark plugs and a condenser...and check to see if the coil is 6 volt. Thanks much.

 

[Bookman]

This may be the dumb question for the day, but I do I tell the difference between a 6 volt and 12 volt coil on my 420? Is it marked on them somewhere?

 

[farmerjack]

what size wires are you using for the battery to the starter and to ground? You need large cables to pass the current with minimum voltage drop. standard 12v cables won't work. I would order the right size from Brillman or Agri-Services.

 

[M-MAN]

Most 12 coils that don't need an external resistor will be stamped as such. You can just measure the resistance. Around 1.5 ohms for a 6v and 3 ohms for a 12v that needs a ballast resistor. 6v across a 1 1/2 ohm coil gets you 4 amps across the points which is exactly what you need. On a good 6v system 4.8 cranking volts is probably all you have. With that voltage drop you need a coil with 1.2 ohms resistance to get the 4 amps across the points you need. The closer you are to 1 ohm across the coil the better off you are.

 

[Bookman]

The ground (positive) is wire mesh and the wire to the starter looks pretty heavy duty. I did not put it on, but it looks close to the 00 welding cable I have on som eof my other tractors...maybe not quite has heavy. Now when my charger is on the tractor, it turns over fine...just does not fire. Tomorrow I am going to check on cleaning the points. Thanks.

 

[Bookman]

Thanks. For chuckles and grins, I stopped by the local John Deere dealer. New coil is $40, but they said the number I had for a six volt parted out to a twelve volt coil. Ummm? Probably something I do not understand. Tomorrow I plan to clean the points and maybe replace the spark plugs. Thanks again.

 

[farmerjack]

use a voltmeter and watch the voltage at the coil (from ignition) to ground to see what voltage you're getting to the ignition system when turning over the engine. I have several 6V tractors (all 4 cylinders) and as long as I have heavy cables and batteries are good they start. Another thing to check. is there a dropping resistor outboard or in the coil? those are for 12 volt systems to use 6v ignition. that will certainly cause you to have an issue when starting.

 

[Bookman]

thanks, will do.

 

[M-MAN]

That's the confusing part about coils. 6v coils and 12v coils are the same IF an external resistor was used somewhere in the 12v system. On a 12v system where there isn't an external resistor of some type the other 12v coil with more internal windings and a higher resistance is used. (usually marked no external resistor required)

 

[Bookman]

It is a six volt coil ...stamped on it. I did some checking today. I get my test light to light up when the ignition switch is on the first position and I touched the test light to a ground and other end to input negative wire on the coil. So I looks like I am getting electricity to the coil. Now I do not get anything when I ground the test light and touch the other end the output positive wire that goes from the coil to the distributor. Does that mean anything? I changed out spark plugs. They were Champion H10 and I put in Autolite 216. The Champions looked bad to me, but of course if they were getting gas and not firing right, I suppose they would look carboned up. I do have a good 6 volt coil I will try but ran out of time today. Gonna watch a little football and contemplate the situation with my tractor.

 

[Bookman]

Went to check the points yesterday and took the distributor cap off. Took off the rotor and went to take off the cover to the points. It did not want to lift off. Kind of end of the day and I wanted to get inside and watch some football so I did not want to get in a hurry and force something. Is it just supposed to lift off or is there something holding it on. I do have the service manual but it does not say. Probably something that is just common sense, but occasionally I have a short supply of that. My guess now is that it just needs points cleaned or replaced, but I will let folks know what it turns out to be. I may not get back to it for a few days. thanks to everyone for all the suggestions and have a Happy New Year.

 

[BushogPapa]

Try setting the Sparkplug gaps to .025 and see if it starts easier..if so, your ignition is very weak..

 

[BushogPapa]

Just REMEMBER...NEVER make it Mad at ya...!!!

Sometimes it don't take much either..!!!!

 

[Bookman]

(quoted from post at 00:57:35 12/29/16) How hard is it to turn over? I have a 420U with a 6V electrical system and It will start down to at least 0º F and maybe more. These are pretty simple and unless there is something wrong, they will usually start if they will turn over. What are you using for oil in the engine? Does it have an external hydraulic pump? What weight oil in the hydraulic system? Do you push in the clutch when trying to start it?

Mine likes just a short full choke and then it will run without any choke after a few seconds.

I assume that you have good spark and that it is timed right. In cold weather the timing is more important than at 40º (tropical here in New Hampshire). You can file a little bit off the end of the rotor to build the spark up just a bit more. New plugs (many different thoughts of the brand and number on this) are probably necessary. Points need to be good and set right. Condensers are a crap shoot. New ones can be worse than the old and if you have one that is good, don't replace it!

With some answers to the above questions, I may have some answers.
CPeter

New points seemed to do the trick. I tried cleaning them and that did not work.

 

[Bookman]

New points did the trick. Cleaning them did not work. I got it started today.

 

[Bookman]

(quoted from post at 13:46:53 12/29/16) Hey Bookman,
This Dubugue series from M through the 430 are notorious for hard starting if the battery and starter are not in top condition as well as being timed and tuned up. Also as Aussie Ken says look at replacing the coil. I too found the wrong one on my old MC, which caused lousy starting as you describe. Good Luck!
John

New points did the trick!!