Ironhead Help with no spark...

iron227 · #1 7th August 2012

I have an issue of no spark with my 76xlh... Prev owner has dyna s ignition on bike and I have put new coil, Plugs, plug wires, and all new main wire harness including hand controls... I'm not sure what can go wrong with the dyna s as it looks pretty basic.... Checked wires from coil back and they are not pinched or frayed any where... The Dyna s looks good as well as I

opened up and the internals and move as I think they should??? Don't know what to check next??? Im hoping it's not needing new ignition...that's my guess. Wanting to get the beast up and running so all help and suggestions are welcomed and appreciated.

IronMick · #2 7th August 2012

I would do voltage drop tests on each circuit. Start with the wire from the batt+ to the 30 amp breaker - check voltage at the batt+ and on each side of the breaker. Then do the same for each wire from the breaker to the ignition key switch, etc. See if at any place the voltage drop is too much.

gungatim · #3 7th August 2012

I would check the easy things first; make sure the switch on the handlebar is good, not grounding out, same with key switch and breaker (as Mick suggested), etc. When you put the new wiring harness in, verify you put the ignition hot on the correct circuit so it is hot with key on. It is an easy mistake to make, if key on gives power to starter but not to ignition, and key off powers ignition but not starter, it is wired wrong. I did it myself once.

ironheadjunkie · #4 7th August 2012

Quote:

Originally Posted by iron227

I have an issue of no spark with my 76xlh... Prev owner has dyna s ignition on bike and I have put new coil, Plugs, plug wires, and all new main wire harness including hand controls... .

Was the bike running before you installed new coil, etc.? What type of Dyna S Single-fire or Dual-Fire? Does it have ONE black modual up at the top (dual-fire) or does it have Two moduals one at top and one at bottom (single-fire)?

iron227 · #5 7th August 2012

I got the motorcycle out of dads garage after he passed away... It had a bad starter relay and solenoid....I completely went through bike from cams to push rods to rocker boxes and trans...new wiring through out and had the rings and pistons checked...almost all new everything... Except dyna s which has just one magnet... Dual fire I guess... That's goods to know as I am new to ironheads... I'm wondering opinions on if I do replace if I should go with points set up or back with dyna s???? Dual or single??? How do I test what I have to be sure that it is the problem... I will be trying the voltage test when I get off as ironmock suggested, anything else I should look for???

98ultra · #6 7th August 2012

When I checked my Dyna S, I checked the HOT side of the coil first. There are two wires here. One goes to the kill switch (supplies the 12v) and the other is a white wire going to the Dyna S. With the key and run switch on, I had 12v on the hot side.

I then checked the other side going to the Dyna S module (Blue wire). At first I had some voltage, I forget what is was exactly but it was low, maybe a volt or volt and a half. I figured, Great, it is bad. I then turned the engine over and had 12v. It was switching on and off after all.

Next I changed the plugs and it fired right up.

98ultra · #7 8th August 2012

Is your wiring like mine? Two wires on one side and one on the other. The white from the Dyna S and the hot from the kill switch one one side and the blue from the Dyna S on the other?
The instructions said if hooked up wrong, it would destroy the module.

If hooked up right, do the voltage readings show the same as mine????? 12v on the hot and a change from 12 to 0 on the other.

98ultra · #8 8th August 2012

Quote:

Originally Posted by iron227

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I don't think I can see any metal under the boot. Do you have the plug wires pushed far enough into the coil??????? to make contact.

trappnman · #9 8th August 2012

while no spark can be frustrating, in reality its not that bad.

Break it down to 1 of 2 things- do you have spark at the points (or EI)? Or juice there, but not at the plugs.

Then you know for sure, what circuit you are working on. It sounds like you do have juice to the points (EI)- I'd have a test light on that, while attempting to start it using the button. if then no juice its a problem with the starting system, not the ignition system per se.

if the coil is good, but still no spark at the plugs, then its either wires/plugs. If plugs and wires are good, then its got to be a short occurring when started button is pushed

have you tried bump starting it? if it is a short in the starter system, it should still start (if your coil/wires and plugs are good) when bump started. if it does not start doing that, then you can, for all practical purposes eliminate that system-

joey81iron85 · #10 8th August 2012

Try the jumper wire trick remove 12v wire to coil then a jumper wire from bat + to coil+ if u have spark then its a wiring issue still no spark prob coil or ei ...I just replaced both on mine new coil went bad in 2 days also I believe u should b running a 3 ohm coil with ei 5 ohm with points