Pamco 'problem' solved!

[anvilsteel]

Sent Pete this message earlier this week, no need for a reply anymore

I've been riding my xs650 (big bore 750cc) sidecar setup (5E6) with the Hughs PMA and Pamco unit (with e advancer and green monster dual coil) for several years now. It has always been a pleasure,...till now.

I put the bike away for about 2 weeks and now it refuses to start.
Fuel is good (with forte additive). Carbs are recently cleaned(BS 34)

I have followed all the troubleshoot-instructions on xs 650.com.

Yes, primary resistance is 3,5 Ω. Secondary with 5K caps (ngk) about 23KΩ.
The wires to the sparkplugs are ok. Sparkplug-caps measure 5KΩ. I have cleaned all the connectors, even did a kill-switch cleaning.
Everything seems in order. There are no problems with the wiring, at least, I cannot find it. They are not broken from the pamco to the e-advancer and from the advancer to the coil (the buzzer on the multimeter buzzes).
With turnkey 'on', both the green and red wire on the coil have about 12,5 Volts. Battery (Odyssee) is full.
Also checked all the grounds and they are ok.
No pins are missing on the Pamco. Advance rod is turning.

The problem is; there is no spark. Tested trying to start with either sparkplug grounded on the fins of the engine.

I also tried the method with an external battery. Same result, no spark.
I changed the plugs for new ones (Iridium). No difference; no spark.

I didn't change anything since when it was running well.

Today I finally solved it

I noticed there was a little bit of oil at the Pamco side of the camshaftcover. On the Pamco itself there was no oil visible. But I decided to clean it with breakecleaner. After letting it vaporize I tested again and,...a beautifull spark!

After replacing the tank and reconnecting the carbs the motor started up with 1 kick!

Perhaps this info is helpfull to someone somewhere...

 

[pamcopete]

anvilsteel,

That's great! But, I am a little surprised that it was oil contamination. I developed a PAMCO for the Honda CB750C DOHC model but never got around to making it market ready. The sensors are located on the left side of the crank in a housing that is under constant oil spraying as the ignition shares the housing with the starter gears. It's basically the same electronics as you have. I have run this prototype system for 4 years and it has never failed. Once in a while I open the cover for inspection, and the entire PAMCO PC boards are saturated in oil with no ill effects. So, I am wondering if in the process of troubleshooting you inadvertently disturbed the real problem (broken wires?) and it has simply gone away.

This system works with the rotor and magnets on the other side of the aluminum plate. The idea was to eventually remove the center hole and cover the other holes to prevent oil from migrating into this section. I never got around to that, so it has run for 4 years with oil freely spraying past the aluminum plate through the huge holes. A testimony to the ruggedness of the PAMCO!

I was also asked about water spray on the PAMCO electronics, and I made this YouTube video showing a CB750 SOHC with a PAMCO still working after being sprayed with water.

That rattle noise is just the clutch basket. They all do that.

 

[anvilsteel]

Thanks for the reply Pete!

If cleaning the pamco has nothing to do with the problem, I guess it will re-appear when I take the xs for a ride. I'll do that tomorrow and hope to enjoy a small tour in the Dutch countryside.
In case of malfunctioning, do you have any suggestions on determining the cause of this problem?

As the wiring is fairly thin I noticed that there where a few rips in the insulation, the corewire itself looked undamaged. I taped those parts with isolationtape and tested it. The multimeter buzzes when both ends of the wire are tested.

 

[scabber]

I had a leaky cam seal oil not a problem with the pamco. I would suspect the wire as the problem. Bend it one way it works another way it don't. Or bare spot grounded. Just guessing enjoy your ride.

 

[anvilsteel]

Took the bike for a little ride today. But I first made sure the wires were ok! I resoldered the wire connections to the Pamco and cut off the bad parts to the e-advancer. To cables are long enough so there wasn't a problem to make new connections.

Noticed during the trip that the clutch needs re-adjusting and the cables should be lubed.
[/IMG]

 

[anvilsteel]

Soooo, thought I solved it.
I retook all the recommended steps for determining if there's a problem with the Pamco. Everything checks out o.k, again...
Did some other work on the XS; new clutch plates, retorqued the head, lubed all cables, new camshaft seals..etc.
Tried to start the bike after a long weekend of maintainance and repair fun,....

No Spark again...

After spraying the pamco with contact cleaner that problem was solved, again... Took the bike for a little ride around the block and everything was fine,...

Nevertheless I've ordered a new Pamco with E-advancer. Maybe with the new one installed the issue will go away...because at this point I am completely in the dark

Btw. I have 3 XS's, so an extra Pamco won't do any harm.

 

[pamcopete]

avisteel,

Well, again I am surprised that a little bit of oil on the sensor would cause a problem, especially with the E-Advancer model because the only component on the sensor board is the hermetically sealed Hall effect sensor, the same one that lives under the cover in my CB750C and is constantly saturated in hot engine oil.

Perhaps it's the sequence that seems to fix the problem. First you try to start it. Then you take some time to clean the sensor. Then it starts. I believe that you have a PMA with a capacitor? Maybe that first attempt just starts to wake up the capacitor. Remember that with the E-Advancer, it has to wake up too. The supply voltage needs to get to the 8 to 9 Volts range for the MCU to wake up, so perhaps there is some residual voltage on the capacitor after the first attempt so the second attempt works. Also, the automatic kill switch is reset after each attempt, or maybe not, maybe there is just enough leftover juice in the capacitor to hold the auto kill switch on after the first attempt, otherwise it can take one complete rotation of the crank to wake up the MCU, so you really have to be sincere with the kick.

Other factors could be in play here, like, do you turn off the headlight when starting?

 

[anvilsteel]

I have no capacitator but an Odysee battery in the sidecar. It's full, I doubt the voltage is the problem. Lights are off, always, on start-up.
I do have the 'old' Pamco which I upgraded with the 60 degree rotor and the E-advancer.

 

[pamcopete]

I have no capacitator but an Odysee battery in the sidecar. It's full, I doubt the voltage is the problem. Lights are off, always, on start-up.
I do have the 'old' Pamco which I upgraded with the 60 degree rotor and the E-advancer.

What is that blob on the transistor?

 

[anvilsteel]

That Blob seems to be some sort of silicon paste. Dunno,..I didn't put it there.

I carefully took the pamco apart. There was some dirt/corrosion on the backside. Cleaned it and reinstalled it.
Sparks nicely now.

 

[pamcopete]

anvil...,

OK. That's great. Did you remove that blob of silicon as well? It looks like it could trap dirt and moisture between the transistor tab and the mounting screw which must be insulated from each other.

 

[anvilsteel]

If that is your recommendation I will remove it. Was it supposed to be there anyway?

 

[TwoManyXS1Bs]

I'd resolder the terminations of that resistor...

 

[pamcopete]

I'd resolder the terminations of that resistor...

Yes, that is a good idea as well. Use a soldering iron of no more than 40 Watts with a very fine tip. Rosin core solder as well. If you do not want to take it apart again, you can solder from the top of the PC board.

 

[anvilsteel]

Thanks for the feedback, I'll do that tomorrow

 

[anvilsteel]

I think it's ok now

I resolderd the resistor and removed all the silicon paste.
When I started the xs after rebuilding the Pamco there were terrible pops (it was like a warzone in my neighbourhood) out of the exhaust I spend all afternoon trying to find the problem.
Finally I noticed that the locating pin from the copper cap on the right side had fallen out. Of course it was unfindable
Fortunately in my shed I have a lathe so this was a quick fix.

The xs is running smoothly again.

Thanks for the support!

 

[KS-1]

To someone who still has exactly the same problem

I had had exactly the same problem but different reason. My system is "Original Pamco Ignition" + "Pamco E-advancer". After some tests, I found the CAPACITOR on E-advancer circuit was dead. Then replaced it to brand new one.

Now my ignition sparks again. Check a capacitor before throw away.

 

[Mailman]

To someone who still have exactly the same problem

I had had exactly the same problem but different reason. My system is "Original Pamco Ignition" + "Pamco E-advancer". After some tests, I found the CAPACITOR on E-advancer circuit was dead. Then replaced it to brand new one.

Now my ignition sparks again. Check a capacitor before throw away.

View attachment 174232

Nice work! That saved you some money!