Is my ignition coil defective?
Thread Starter
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Seasoned HDF Member
Joined: Nov 2006
Posts: 5,894
Likes: 1,908
From: East Coast, USA
Is my ignition coil defective?
Yesterday, I took my 1993 Fatboy out for a run sponsored by one of the local clubs. I haven't been using this motorcycle much lately and the bike was running poorly. The bike was lacking power, missing and backfiring. The bike ran poorer the hotter it seemed to get. Finally, the bike just gave-up and I had to call AAA for a flatbed ride home.
The bike has approximately 102,000 miles.
I'm currently running with a Crane Cam Single Fire Performance Ignition Coil (8-3001). The coil is about 27 years old with about 83,000 miles on it.
I measured the resistance of both the primary and secondary circuits. I'm getting:
Primary:
2.8 ohms, 2.8 ohms
Secondary
9.54K ohms, 9.52K ohms
Would this be considered out-of-spec for this coil? Should I just replace it? The plastic housing on the coil seems very weathered and possibly brittle.
TIA!
The bike has approximately 102,000 miles.
I'm currently running with a Crane Cam Single Fire Performance Ignition Coil (8-3001). The coil is about 27 years old with about 83,000 miles on it.
I measured the resistance of both the primary and secondary circuits. I'm getting:
Primary:
2.8 ohms, 2.8 ohms
Secondary
9.54K ohms, 9.52K ohms
Would this be considered out-of-spec for this coil? Should I just replace it? The plastic housing on the coil seems very weathered and possibly brittle.
TIA!
Grand HDF Member
Joined: Apr 2007
Posts: 3,727
Likes: 3,071
From: Brighton, MI
What brand nose cone cam sensor? Not sure what your coil secondary resistance numbers should be on aftermarket coil, but your manual should tell you the ball park numbers. Primary seems OK.
Does it start up after things cool down? Sounds like it wouldn't hurt one bit to replace that coil (because it sounds like it is long in the tooth). But look at your nose cone ignition first.
Does it start up after things cool down? Sounds like it wouldn't hurt one bit to replace that coil (because it sounds like it is long in the tooth). But look at your nose cone ignition first.
HDF Community Team
Joined: Dec 2005
Posts: 5,421
Likes: 2,621
From: NC USA
Just because a coil ohms out good doesn't guarantee it'll fire consistently, or at all. Just checks for open or shorted and then it's 50/50.
Another vote for the possibility of failing cam sensor in the nose cone.
Wait... single fire coil? What ignition does it have? Stock Evo ignition won't fire a single fire coil.
Another vote for the possibility of failing cam sensor in the nose cone.
Wait... single fire coil? What ignition does it have? Stock Evo ignition won't fire a single fire coil.
Thread Starter
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Seasoned HDF Member
Joined: Nov 2006
Posts: 5,894
Likes: 1,908
From: East Coast, USA
What brand nose cone cam sensor? Not sure what your coil secondary resistance numbers should be on aftermarket coil, but your manual should tell you the ball park numbers. Primary seems OK.
Does it start up after things cool down? Sounds like it wouldn't hurt one bit to replace that coil (because it sounds like it is long in the tooth). But look at your nose cone ignition first.
Does it start up after things cool down? Sounds like it wouldn't hurt one bit to replace that coil (because it sounds like it is long in the tooth). But look at your nose cone ignition first.
Just because a coil ohms out good doesn't guarantee it'll fire consistently, or at all. Just checks for open or shorted and then it's 50/50.
Another vote for the possibility of failing cam sensor in the nose cone.
Wait... single fire coil? What ignition does it have? Stock Evo ignition won't fire a single fire coil.
Another vote for the possibility of failing cam sensor in the nose cone.
Wait... single fire coil? What ignition does it have? Stock Evo ignition won't fire a single fire coil.
Is the recommendation to replace the nose cone sensor and the ignition coil?
Club Member
Joined: Mar 2009
Posts: 66,125
Likes: 51,440
From: Niles Canyon Ca.
Found the issue, common failure item on the older bikes. Pick up unit and go from there, coil is probably ok.
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Grand HDF Member
Joined: Aug 2008
Posts: 3,601
Likes: 9,915
From: Florida's gorgeous East coast
BINGO...!!!!
Good picture of a failed/failing unit in the nose cone. Replace that and see what happens next. ONE thing at a time.
From the OP:
"I haven't been using this motorcycle much lately"
While you're at it...get the battery load tested. Weak batteries can contribute to all kinds of gremlins.
Good picture of a failed/failing unit in the nose cone. Replace that and see what happens next. ONE thing at a time.
From the OP:
"I haven't been using this motorcycle much lately"
While you're at it...get the battery load tested. Weak batteries can contribute to all kinds of gremlins.
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Seasoned HDF Member
Joined: Mar 2010
Posts: 21,115
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From: Poolville
This should cure your problem.. Standard Motor Products MC-SPA2...
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