Coil

[ajhbike]

JD 3020-Gas, 12 volt with alternator...working through the fuel, air, spark trinity....the tractor dies every 5-10 mins. l am thinking coil...I have a spare that is for all farmalls and internationals. It says "Internal Resistance. For straight 12 volt systems without series resistance"....does that mean I do NOT need an external resister? Thank you.

[tst]

yes, no resistor needed

[Bezirk]

correct , no external resistor needed .

Berlin

[ajhbike]

Here's another one. This 3020 turns over very heavy and I am wondering if I should get a hotter coil to get the thing turning over faster. I am in the process of hooking up the 2nd 12V battery (keeping it 12V) and I am thinking with double the CCA's and a hotter coil I can get that thing really turning over. The problem with coils I have bought in the past is that they never say what the output is...even when researching. I have seen only 1 coil that says it puts out 55,000V....a Flamethrower brand??? What is considered "normal" output and what is considered "hot"?

[Eugene]

All you need for a coil is one to cause spark to jump the gap and ignite the air fuel mixture.

The coil, any coil, will not cause the engine to crank/turn over faster.

Check the battery condition, corrosion on cable, battery terminals, corroded battery cables. If that doesn't solve the problem, have the starter checked.

[ajhbike]

Great counsel,Eugene thank you.

Batteries are both new and good condition, new battery cables. After replacing the coil, distributor cap, points, plug wires and plugs, I checked the spark from the coil to the distributor and from the distributor to each plug is pretty thin and yellow....on another site they mentioned that is should be strong and bluish...not sure how more current changes the color of a spark. I am wondering if the wiring for the ignition and start button should be upgraded from #14 wire to at least 12 once I get the batteries hooked up and contacts cleaned. The ignition switch spades are pretty gunked up. The zenith carb is currently being rebuilt so at least I will have a good base of good carb, good fuel line, good fuel pump

I will say that it is amazing the "technology improvements" on the 51 SC vs the 66 JD. SC has about 6 wires and this thing has harnesses and bundles! Very interesting to learn about this too.

[Eugene]

Check the ignition timing. A bit to early will make the engine hard to start.

Set the ignition timing so that it fires just a smidgen after TDC when cranking the engine over. See what happens.

Edit: Faulty condenser will cause a weak yellow spark.

[ajhbike]

okay, I will have to dive into the operators manual to determine how to time.
Here is a stupid question....or a stupid assumption....if the firing order is 1,4,3,2 then it doesn't matter where the #1 plug wire is plugged into the dist cap as long as the #4 plug is plugged in next to it and then #3 and #2 assuming the rotor turns clockwise?

[Slim140]

The #1 plug wire has to be in the right position on the cap when the dist. fires on # 1, it HAS to be in time. The cap may have a #1 on it, if not do a search on it for your tractor and you can probably find where #1 is.

If your wires are off then your firing will be off. If you have #4 wire where #1 should be then cylinder #4 will be firing when #1 should be, make sense?

[ajhbike]

yep, got it. Thank you.

[ajhbike]

does it run clockwise?

[ajhbike]

To continue with the JD 3020 topic...do you know if the choke lever should be horizontal when "open"? Mine seemed to be at about a 30 degree angle or partially closed when in the "open" position. The manual for the Zenith shows the choke horizontal and it might be the cause of the rough running engine.

[Don McCombs]

Here's a photo of a rebuilt 3020 carb. Don't know if that helps or not. http://www.yesterdaystractors.com/John- ... 4CARB.html

[ajhbike]

I sent my carburetor out to be rebuilt to yesterday's tractors it is a zenith . What is sticking in my craw is is that I remember when I took it off the tractor that playing with the choke plate I could not get it to get horizontal in position . It was at best open 60% . the tractor was running rich all the time and stalling out when I would take the RPMs up . now I am thinking that the reason it was running rich was because it wasn't getting enough air .