​​​​​​​28k miles
Mikuni carb
aftermarket HD oil pressure sensor
14" bars
no other changes which could affect mechanical or electrical

Been working on this since mid-September, rode fine until one day it wouldn't start. Started with just the service manual but recently picked up the electrical diagnostic manual. Assumed it was a spark plug issue before starting any diagnostic testing so both plugs are new.

Testing results:
Battery 12.62v and on the trickle charger
CKP (crank position sensor) 1.8v AC while engine spinning
ignition coil primary circuit test .5 ohms each side
ignition coil secondary circuit test 6.2k ohms each side
rear spark plug wire 3.3k ohms (lower than recommended)
front spark plug wire 6.81k ohms (higher than recommended)
Spark test done with both plugs in engine, used plug from my truck to test spark by connecting to ground (like the HD spark tester).
commpression ~140 psi both cylinders

Only test ouside of normal was the plug wires but one of them is low so that shouldn't cause a spark issue right? I don't have spark at either plug. Any ideas or new things to test?

I have read as many posts as I can find on this forum and others but couldn't find the answer.

 

Are you testing for spark with the plugs removed? If so, they will not spark without compression. Leave plugs in and check for spark with a spare plug. Do you have power at the coil with switch on? Is fuel pump running for a few seconds when switch is turned on? Do you have fuel pressure? Any codes? Battery is a bit low at 12.62V. Load test battery.

 

Yes, I'm testing for spark with both plugs in the engine and using a spare plug from my truck. And I grounded the plug to the frame.

Yes there is power at the coil, the middle pin from the harness is showing 12.6v.

It has a carburetor and there is fuel squirting into the carb. I don't think fuel is an issue.

The battery was low yesterday and I'm sure it is fully charged now. I don't have the equipment to do a load test on the battery, do you really think the battery being a little low could cause a no spark?

 

Battery voltage after full charge: 13.18v

I also tested the resistance at the CKP plug 0.5-0.6 ohms which is quite low. Does this mean I need a new CKP even if it passed the AC voltage test?

 

Installed new crank position sensor and plug wires...it started! It was a little rough at first but eventually smoothed and idled just fine. I let it run for a while and warm up before shutting it off.

 

FYI - the CKP will pass the HD test and still be bad. I always look for a tach signal while cranking. If I see a few hundred RPM while cranking, the CKP is good to go! CKP failure on older bikes is not uncommon.

 

interesting, I didn't realize the CKP affected the tach. Unfortunately I don't have a tach...I don't think it was an option on the Wide Glide but I think some Dynas in '03 had it.

 

The CKP creates it's own voltage signal which is the RPM input to the ECM. It sends the signal to the ECM to wake up the system after initial key up. For instance, on an EFI bike the fuel pump comes on at key up. If the bike isn't cranked the ECM doesn't see the flywheel move and shuts down the system. Then the pump comes on when the engine is cranked. So if using a scan tool, you cal also watch tach signal.