Happy, happy, happy

[redglbx]

I’ve had an issue with my red 76 that I’ve owned since new where it’s had a “chuff” out of the tailpipe for probably 6-8yrs now, it has gradually gotten worse.. so when my back would allow me to work on it I have changed the Dyna ignition module out for the Prestolite that I had installed years ago (changed it back to the Dyna later),, as well as changing the plugs multiple times (standards to iridium & back) and adjusted the valves to different settings (now at the factory .004in) and adjusted the carbs to many different settings and I have done several compression tests as well as multiple leak down tests with all showing fine.. But the chuff persisted…

So some time ago I was reminded of Chris Jacobs PhD (Jacobs Electronic Ignitions) that had a strong belief that solid core wires would create a level of EMI that could cause issues with the transistors & resistors in electronics that could cause them to fail at the worst or cause a misfire all do to the EMI created by solid core wires.

So Dr Jacobs marketed his own variable spark ignition along with his own spiral core resistor core plug wires to prevent all this. His wires along with other better quality like MSD wires had an advertised resistance of 50 ohms per foot and even the lower quality spiral core wires managed to have a rating at or below 500 ohms per foot. While most resistance plug wires managed runs 5k-25k ohms per foot. So anyway I bought 25ft of decent spiral wound plug wire figuring it can’t hurt and the solid core wire we all use on these old beasts may be contributors to why so many Dyna Ignitions have and do fail,, nothing to lose but the time to make up new plug wires..

So long story,, I made the 2 wires on the left hand cylinder bank (#2 & 4) figuring they are closest to the Dyna ,, I made them up and fired my bike up for the first time in several years, , had some trouble,, it helps to turn the “kill” switch to the run position !… Anyway the exhaust chuff was still there and got worse as the motor warmed (well shite !)

So I went ahead and figured I was 1/2 to a New set of wires so I made up some for the #1 & #3 wires…..Lo & behold the chuff is gone !!! Hallelujah! Amen, thank you Jesus ! Happy, happy, happy ! I let it run for a very long time and it just sat there and purred ,, she hasn’t run like this in a very long time…

So now it’s a matter of changing the timing belts since it’s been a while, I’ll recheck the ignition timing while I’m there and check the carb sync as well ,, don’t think I’ll find much as it’s running quite well,,, just needs the cobwebs blowed off now ,, happy, happy, happy !

I hope this may help someone here as well..

[Fred Camper]

Do you have a link to the wires? Many with dynas want to replace them before the dyna goes bad again.

[redglbx]

Fred, I bought Ton’s black 8mm Performance spiral wound wire off of eBay,, it was $1.68/ft,,, no complaints, they seem to work fine.. They don’t have the low ohms/ft like the MSD wires do where they are advertised at less than 50 ohms/ft and the one’s I’ve measured over the years are actually near zero. The Ton’s aren’t that low but they are in the ball park and no EMI..

For years after reading Chris Jacobs book with his concerns for the EMI generated by the solid core wires taking out the electronics in the new ignition systems I’ve had concerns but quite frankly just forgot about it for a while..when we had a discussion here a bit ago and it was mentioned about failing Dyna ignitions it brought all those thoughts back,, don’t know if it is truly a contributor or not but going with the resistor wires sure won’t hurt, my .02

[theailer]

Awesome! It's an absolute blast to finally be able to fix something this elusive =)
EMI is no joke and can be incredible hard to troubleshoot.

[redglbx]