1979 75 hp Chrysler motor CDI is screaming any suggestions

h20speed

Cadet
Joined
Aug 13, 2024
Messages
7
Just got the boat and the CDI box is screaming in on position I think it might be the dist trigger but I don't want to jump to conclusions help needed thank you if u can any advice helps
 

Nordin

Commander
Joined
Jun 12, 2010
Messages
2,592
What kind of CD box do you have?
There are four OEM boxes and one aftermarket if I do not remember wrong.
Two from manufacture Delta and two from Motorola and one from aftermarket CDI Electronics.
The oldest one from Delta with two power transistors mounted on the housing would make a high pitched noise when powered with 12VDC.
The aftermarket CD box from CDI Electronics do the same and it is normal for these two typs of boxes.
The other typ from Delta I have no experience of and the two typs from Motorola do not have any noises.
Check which one you have.
BTW Do you have spark?
Is the engine running as it should?
 

h20speed

Cadet
Joined
Aug 13, 2024
Messages
7
What kind of CD box do you have?
There are four OEM boxes and one aftermarket if I do not remember wrong.
Two from manufacture Delta and two from Motorola and one from aftermarket CDI Electronics.
The oldest one from Delta with two power transistors mounted on the housing would make a high pitched noise when powered with 12VDC.
The aftermarket CD box from CDI Electronics do the same and it is normal for these two typs of boxes.
The other typ from Delta I have no experience of and the two typs from Motorola do not have any noises.
Check which one you have.
BTW Do you have spark?
Is the engine running as it should?
It's a DC 115 3301
 

h20speed

Cadet
Joined
Aug 13, 2024
Messages
7
What kind of CD box do you have?
There are four OEM boxes and one aftermarket if I do not remember wrong.
Two from manufacture Delta and two from Motorola and one from aftermarket CDI Electronics.
The oldest one from Delta with two power transistors mounted on the housing would make a high pitched noise when powered with 12VDC.
The aftermarket CD box from CDI Electronics do the same and it is normal for these two typs of boxes.
The other typ from Delta I have no experience of and the two typs from Motorola do not have any noises.
Check which one you have.
BTW Do you have spark?
Is the engine running as it should?
I can't get the engine to run or spark but it will turn over
 

Nordin

Commander
Joined
Jun 12, 2010
Messages
2,592
Okey, outboardignitiondotcom have troubleshoot chart for it.
This system is simple, you need power to the CD box from keyswitch blue wire, black to good ground and white/black to distributor.
When checking the CD box you have to have the keyswitch in ON position (12VDC to right terminal at distributor if you have a distributor with a preamp (electronic) and blue wire at CD box.
Set the top cylinder at TDC, remove the plug and ground the spark plug to ground.
Loose the white/black wire from distributor and scratch it to ground.
Each time you scratch the plug should spark.
If it does the CD box is good and there are something wrong in the distributor. Check the HT wires, rotor, rotor pin and the preamp.
 

h20speed

Cadet
Joined
Aug 13, 2024
Messages
7
Okey, outboardignitiondotcom have troubleshoot chart for it.
This system is simple, you need power to the CD box from keyswitch blue wire, black to good ground and white/black to distributor.
When checking the CD box you have to have the keyswitch in ON position (12VDC to right terminal at distributor if you have a distributor with a preamp (electronic) and blue wire at CD box.
Set the top cylinder at TDC, remove the plug and ground the spark plug to ground.
Loose the white/black wire from distributor and scratch it to ground.
Each time you scratch the plug should spark.
If it does the CD box is good and there are something wrong in the distributor. Check the HT wires, rotor, rotor pin and the preamp.
It did that yesterday when I troubleshooted it I think it's the pickup in the dist
 

Nordin

Commander
Joined
Jun 12, 2010
Messages
2,592
New preamp is 170 dollars or more...... uuuhh.
Ebay maybe have cheaper.
 

Nordin

Commander
Joined
Jun 12, 2010
Messages
2,592
Do the troubleshoot as per outboardignitiondotcom.
Scratching the white/black wire to ground and check if you got spark from CD box without using the preamp.
Check and clean the inside of the distributor cap.
Check the HT wires from distributor to spark plug rubber boot.
Check the battery voltage when you crank the engine.
The CD box need at least 9,5-10 Volt to work.
 
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