1971 Johnson 60hp cdi box issue

C

chasebowers2003

Cadet
Joined
Jul 19, 2021
Messages
16
I recently bought a motor to fix up. Previous owners you could tell were messing with wiring so I took it all off and I’m trying to understand everything as I put it back on. I’m working on trying to get spark out of the engine, I saw the amplifier had lots of corrosion and wasn’t sending power out. I bought a cdi box, installed it and get power where it needs to be but whenever I touch the wire that’s supposed to go to the coil to a grounded surface or the coil wire. The power drops to 0 and I’m not getting spark still. Anyone know anything to help me?
 
R

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,499
The amplifier does not put a steady 12 volts to the coil !-----That is NOT the way it works.-----Have you had the flywheel off to set the breaker points at 0.010" ? ----Check the anti-reversing spring ?-----Cleaned the distributor cap and rotor ?
 
C

chasebowers2003

Cadet
Joined
Jul 19, 2021
Messages
16
racerone said:
The amplifier does not put a steady 12 volts to the coil !-----That is NOT the way it works.-----Have you had the flywheel off to set the breaker points at 0.010" ? ----Check the anti-reversing spring ?-----Cleaned the distributor cap and rotor ?
Click to expand...
Haven’t had the flywheel off yet but was planning on it. First time with a cdi box so I didn’t know and cdi box was putting out around 45 volts if that’s normal. What’s the anti reversing spring and where the distributor. Sorry new to this engine
 
R

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,499
You have to take the flywheel of to find the distributor cap.----Work carefully as parts may be expensive.
 
C

chasebowers2003

Cadet
Joined
Jul 19, 2021
Messages
16
racerone said:
The amplifier does not put a steady 12 volts to the coil !-----That is NOT the way it works.-----Have you had the flywheel off to set the breaker points at 0.010" ? ----Check the anti-reversing spring ?-----Cleaned the distributor cap and rotor ?
Click to expand...
Did what you said and still no spark
 
R

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,499
Remove coil from distributor cap.----Note , Wire is threaded in.-----Test and see if spark comes out of the coil.
 
F

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
You better be careful with your experimental "testing". You can blow that amplifier almost instantly.
 
C

chasebowers2003

Cadet
Joined
Jul 19, 2021
Messages
16
So long story short I bought this motor from a guy who said it was running two years ago. Starting to regret my purchase because I’ve re gapped the points to .010 and put on a new cdi box which isn’t cheap. All that and no spark. I tested the coil and I’m new to electrical issues but the only reading I was able to get was the ground to power wire and it was .4 ohms. Idk if that’s good because I couldn’t find much on the internet. Any help would be appreciated
 
F

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
That probably is ok. You need to isolate the problem before fixing things or buying expensive parts.

1. Disconnect the coil and unbolt it from the mount. Now remove it from the distrubutor cap by unscrewing the wire frpm the cap (rotate the whole coil & wire to unscrew it.)

2. Remount the coil and rig up a spark gap off the end of the threaded terminal. Reconnect the primary wire.

3. Disconnect the wire leading to the points.

4. Turn ignition switch on.

5. Lightly brush the points' wire across an unpainted, grounded surface. You should see a flurry of sparks across your spark gap. If you do, everything up to that point is working and your problem is elsewhere, such as points, distributor , etc.. If no sparks, work backward through the circuit, starting with the voltage at the purple wire input to the amplifier. Should be close to 12 Volt.
 
C

chasebowers2003

Cadet
Joined
Jul 19, 2021
Messages
16
F_R said:
That probably is ok. You need to isolate the problem before fixing things or buying expensive parts.

1. Disconnect the coil and unbolt it from the mount. Now remove it from the distrubutor cap by unscrewing the wire frpm the cap (rotate the whole coil & wire to unscrew it.)

2. Remount the coil and rig up a spark gap off the end of the threaded terminal. Reconnect the primary wire.

3. Disconnect the wire leading to the points.

4. Turn ignition switch on.

5. Lightly brush the points' wire across an unpainted, grounded surface. You should see a flurry of sparks across your spark gap. If you do, everything up to that point is working and your problem is elsewhere, such as points, distributor , etc.. If no sparks, work backward through the circuit, starting with the voltage at the purple wire input to the amplifier. Should be close to 12 Volt.
Alright I believe I did what you said. Tested two coils and neither had spark coming out the end when touched bare metal. My cdi is new and the old one was shot so I don’t really have a benchmark to go off of but I’m getting over 12 volts to the cdi but I’m not getting anything out of it, all I’m getting out of the wire connected to the coil is 1volt as soon as I turn the throttle off. I am also getting 12 volts to the points
Click to expand...
 
C

chasebowers2003

Cadet
Joined
Jul 19, 2021
Messages
16
I did a spark gap test with the coil and didn’t see any spark. The purple wire into the cdi box is over 12 volts and there’s over 12 volts going to the points. Any help?
 
F

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Did you follow my instructions in your other thread exactly? If you did, you probably have a bad amplifier or coil. Take your pick. BTW, it would be better to stick with one thread so we can follow your progress.
 
C

chasebowers2003

Cadet
Joined
Jul 19, 2021
Messages
16
F_R said:
Did you follow my instructions in your other thread exactly? If you did, you probably have a bad amplifier or coil. Take your pick. BTW, it would be better to stick with one thread so we can follow your progress.
Click to expand...
Sorry I’m new to this whole forums things. I was only getting reply’s when creating new ones that’s why I did that. But I just recently bought a cdi box because the old one was extremely corroded. Is there a way to test if it’s working properly. It is getting power to it but no power out to the coil unless I remove the wire from a ground. Some guy told me it does supply constant power and let it at that.
 
F

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
I think I told you how to test it (and the coil at the same time). Anything more sophisticated requires some test equipment.

You don't seem to understand how it works. With the key turned on, 12V is supplied to the amplifier. That 12V is increased (amplified) to 300V and stored in a capacitor until time to fire. Something has to tell it when it is time to fire, and that something is the breaker points. When they open, the 300V is discharged to the coil (Capacitor Discharge Ignition). The coil builds that up to several thousand volts to make a spark. Then the process repeats. Note, that is 300V discharge to the coil in a very fast pulse--too fast for an ordinary voltmeter to indicate it, not a constant voltage.
 
You must log in or register to reply here.
Top