Pamco Electronic Ignition Issue on CB450

[Ted1375]

Hey guys,
So I have a 74 CB450 that I’ve been going through and it currently isn’t getting spark on the right side. I installed a Pamco v3 back in 2016. I have trouble shot the issue down to the Pamco electric ignition and mostly likely a component on either the sensor boards or the advancer board. I know Pamco isnt a company anymore but has anyone ever sourced a schematic for their circuit boards? I’m going to start checking components on the board but any advice/experience would be great! Thanks in advance

I’ve checked:
-Wiring/everything is good from the sensor to the advancer and advancer to coils
-Battery is new and charged fully
-spark plugs and caps check out
-coils check out
-getting power to the coils and to the advancer so not a ignition switch/kill switch issue

 

[ancientdad]

Here's the only one I could find with any actual module repair

https://www.vintagehondatwins.com/forums/threads/texasaggie%E2%80%99s-first-bike-build.132/#post-1480

Did you ever replace the original separate rectifier and regulator with a modern rec/reg unit? If not, voltage spikes can kill a Pamco if above 14.5v

 

[WintrSol]

I found the lack of strain relief at the circuit board inside the plastic box led to a break in one of the wires at the board. That led to an intermittent failure that seemed to Ohm out OK. I stripped and re-soldered the wires and put a knot in the cable that would keep a tug on it from pulling on the board, and pull on the box instead.

 

[Ted1375]

Ahh ok, I’ll take a deeper look at the solder points today. Thanks

 

[Ted1375]

Here's the only one I could find with any actual module repair

https://www.vintagehondatwins.com/forums/threads/texasaggie%E2%80%99s-first-bike-build.132/#post-1480

Did you ever replace the original separate rectifier and regulator with a modern rec/reg unit? If not, voltage spikes can kill a Pamco if above 14.5v

Yes I did replace the rec/reg with a modern one at the time of installing the pamco

 

[ancientdad]

Yes I did replace the rec/reg with a modern one at the time of installing the pamco

If you didn't buy this one you wasted money.

12V Single Phase Regulator/Rectifier - Sparck Moto

Sparck Moto - Modern Gear for your Vintage Ride

www.sparckmoto.com

 

[Ted1375]

Just a little update on my no spark on the right plug issue. I’m basically 99% confident the main chip on the Pamco advancer board is bad. I was able to trace the signal of the white wire(right side coil) and the signal enters the top side of the chip where the arrow points to and exits the bottom side where the other arrow points to. I can see a signal entering the chip and nothing exiting. On the working side(green wire) I can see a signal entering and exiting. Unfortunately this is probably the end of the road for the Pamco. Back to points or another electric ignition option. Anyone ever use the tytronic ones on eBay?

 

[GaryJames]

If you are sure the integrated circuit is at fault why not check your local electronic components store for a replacement? It looks like it is in a plug in DIP package so easily removed etc.protect the new IC from static discharge when fitting.
do you have a Fry’s Electronics nearby?
quote the manufacturer ( Texas Instruments ) and both numbers of the IC you have.
I am sure the price will be quite low.

 

[GaryJames]

Might not be as simple as direct replacement as it is a microcontroller ( small computer ) so will likely need programming first . the original manufacturer is no longer in business so he would have the code….
apologies

 

[Ted1375]

Yeah from what I read that chip is programmed by Pamco so likely I wont be able to get a replacement.