Ignition coil v fire II
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From: Eastern NC
Ignition coil v fire II
I recently replaced my ignition coil with a new HD coil with the correct part # 31609-80 purchased from dealer. At the time I checked the secondary resistance and found it to be closer to the spec for V fire III at 10,000 ohms. The v fire II calls for 16.5-19.5k ohms and this always bothered me. I recently fouled a set of plugs due to too much enrichment with the S&S carb.
I replaced the plugs and grounded them out to check the spark......was not impressed with yellowish spark, expected to see blue.
Vodoo has a replacement for the 31609-80 that is specifically made for the V fire II ignition that I have and it is made in USA. Primary is 4.0 ohms and the bible calls for 3.3-3.7 ohms.
Close enough? Dynatec has the DC6-1 and primary is 3.0 ohms. As I understand, the lower the primary resistance the physically hotter the coil will get so I think 4.0 Ohms would be a better choice?
I replaced the plugs and grounded them out to check the spark......was not impressed with yellowish spark, expected to see blue.
Vodoo has a replacement for the 31609-80 that is specifically made for the V fire II ignition that I have and it is made in USA. Primary is 4.0 ohms and the bible calls for 3.3-3.7 ohms.
Close enough? Dynatec has the DC6-1 and primary is 3.0 ohms. As I understand, the lower the primary resistance the physically hotter the coil will get so I think 4.0 Ohms would be a better choice?
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From: la la land jerzey
most electronic ignitions TODAY are all 3 OHMs - old original first edition ignitions were 5 OHMs so is points 5 OHMs
the only number your looking for is across the two terminals for cross/over OHMs - get a 3 OHM coil - dont re jet the carb it thought the charging system was dead as well as the battery as the coil your using was around 10,000 volts at best using a 5 OHM in a 3 ohm system
the only number your looking for is across the two terminals for cross/over OHMs - get a 3 OHM coil - dont re jet the carb it thought the charging system was dead as well as the battery as the coil your using was around 10,000 volts at best using a 5 OHM in a 3 ohm system
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Stellar HDF Member
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From: Eastern NC
Thanks John, My ignition is all original V fire II
ignition. The HD coil 31609-80 I have is 3.5 ohms, read across the two terminals.
Troubleshooting today I found one of my new 8.8 accel wires wires open. The wires were new last year and the end must have started to fail when I replaced the coil last year.
I hear you John, here are the descriptions for both 3 and 4 ohm coil:
Andover Black/Green Voodoo Dual-Fire High Power Ignition Coil - 3.0 OHM - 16064
FITS: Big Twin models 1984/1999 and Sportster models 1985/2003 with V-Fire III electronic ignitions.
Here is the description for the 4.0
Andover Black/Green Voodoo Dual-Fire High Power Ignition Coil - 4.0 OHM - 16062
FITS: All Shovelhead models 1980/1984 and Sportster models 1980/1982 with V-Fire II electronic ignitions and Sportster models 1983/1984 with V-Fire III ignitions. Specifications
ignition. The HD coil 31609-80 I have is 3.5 ohms, read across the two terminals.
Troubleshooting today I found one of my new 8.8 accel wires wires open. The wires were new last year and the end must have started to fail when I replaced the coil last year.
I hear you John, here are the descriptions for both 3 and 4 ohm coil:
Andover Black/Green Voodoo Dual-Fire High Power Ignition Coil - 3.0 OHM - 16064
- These high voltage USA made coils are available in 45,000 Volt Voodoo versions
- These coils bolt into OE position
- High voltage coils help increase performance, fuel economy and offer easier starting
- Replaces HD# 31614-83 and 31620-88A
FITS: Big Twin models 1984/1999 and Sportster models 1985/2003 with V-Fire III electronic ignitions.
Here is the description for the 4.0
Andover Black/Green Voodoo Dual-Fire High Power Ignition Coil - 4.0 OHM - 16062
- These high voltage USA made coils are available in 45,000 Volt Voodoo versions
- These coils bolt into OE position
- High voltage coils help increase performance, fuel economy and offer easier starting
- Replaces HD# 31609-80
FITS: All Shovelhead models 1980/1984 and Sportster models 1980/1982 with V-Fire II electronic ignitions and Sportster models 1983/1984 with V-Fire III ignitions. Specifications
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Stellar HDF Member
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From: Eastern NC
So what's the difference between the v fire II and v fire III? Does the v fire III use VOES? Info is scarce. I have the original owners manual and the service manual for my 1983 FXR and neither says anything about either. I'm going to call Andover on Mon, they were the manufactures for coils for Harleys at one time.
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From: Eastern NC
Troubleshooting today I found one of my new 8.8 accel wires wires open.
The wires were new last year and the end must have started to fail when I replaced the coil last year.
I took the boots off and found the end that goes into the coil to have a problem. On the good end that goes on the spark plug I could see the insulation was cut back and the carbon core was tucked under the metal clamp when it was crimped. On the coil end, the carbon core was not tucked under and was almost flush with the insulation. I got carbon dust all over my fingers when I pried the crimp open so it seems that the core may have been laying against the metal making poor contact and getting blown apart as a result. It was never tucked under.
I cut back the insulation leaving the core about 1" long and tucked it under the clamp when I re-crimped it. I took an Ohms reading 4.7 K ohms, with in 10" wire spec of 25-58K.
Put everything back together and she fired up 1st crank!! Took her for a 10 mile run and it ran like a champ....all is good for now.
Lesson learned.....be very careful with spark plug wires. I had no idea that the ends were just crimped around the very pliable jacket of the wire.
The wires were new last year and the end must have started to fail when I replaced the coil last year.
I took the boots off and found the end that goes into the coil to have a problem. On the good end that goes on the spark plug I could see the insulation was cut back and the carbon core was tucked under the metal clamp when it was crimped. On the coil end, the carbon core was not tucked under and was almost flush with the insulation. I got carbon dust all over my fingers when I pried the crimp open so it seems that the core may have been laying against the metal making poor contact and getting blown apart as a result. It was never tucked under.
I cut back the insulation leaving the core about 1" long and tucked it under the clamp when I re-crimped it. I took an Ohms reading 4.7 K ohms, with in 10" wire spec of 25-58K.
Put everything back together and she fired up 1st crank!! Took her for a 10 mile run and it ran like a champ....all is good for now.
Lesson learned.....be very careful with spark plug wires. I had no idea that the ends were just crimped around the very pliable jacket of the wire.
Last edited by Redrodyankneck; Nov 29, 2020 at 06:06 PM. Reason: typo
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From: Cental, MI
Yet, I cannot think of a better method!!!! Use the Correct tools, in the Correct Manner, and all is Good!!!
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