Question about CB360 coil wiring

hillset

Active Member
Sorry if this is violating the rules but I have a question based on my previous post in the engines forum that I think would be more appropriate for the electrical forum. Previous post is here: http://www.dotheton.com/forum/index.php?topic=75770.0

I'm trying to wire up a pamco electronic ignition to my CB360 and I've been having trouble getting the bike running. Originally, I wired the pamco exactly how its described on the CB360ignition.com site - pamco white to right coil blue wire + pamco green to left coil yellow wire, but when I checked the timing with my timing strobe I found the right spark plug was firing at the LF mark on the alternator and vise versa for the left plug.

I switched the wires from the pamco so the pamco green wire is now flipped and going to the right coil's blue wire and the pamco white wire is now going to the left side coil's yellow wire, and I can confirm the timing is pretty spot on based on the strobe with the left side plug firing at the LF mark, but I'm still not getting ignition.

One thing that's troubling me is that yesterday I accidentally plugged the yellow wire from the left coil into the blue wire for the right coil with the pamco green + pamco white plugged into the left coil and the bike fired right up. It was idling a little fast but wasn't having any problems. The only reason I noticed there was an issue was because I wasn't getting spark on the left cylinder so I went back and double checked my wiring, which is when I found my problem.

My question is how could I be getting a correctly timed spark causing right cylinder ignition with the blue and yellow coil wires both going into the same coil and essentially no timing wire going into that coil? I'm assuming since I was able to idle the bike when I did this, the primary and secondary coils, spark plugs, and starter motor are all in good shape and my issue is likely related to problems with the wiring somewhere?

Thanks to everyone for your help, if anyone has any ideas on what to try I'll definitely appreciate it. I've included a diagram of the pamco wiring from the site below, and you can see pictures / video on my previous post.
 

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How much was the bike taken apart? Possible the ignition coils got put back onto the wrong side? Something else that might have been swapped from left to right? Does this PAMCO unit still use the mechanical advance?
 
Hey sonreir thank you so much for your reply. The coils have not been off the bike since the last time the bike was running, so I’m pretty confident they are on correctly. I’ll go over the wiring to make sure I haven’t swapped anything else from left to right but I can’t think of anything else that could be switched. I’ve double checked right coil is going to right plug in the right cylinder and same for the left. Anything else you can think of that could be switched?

Pamco uses an electronic advancer. It’s a unit that fits over the pamco unit into the notch on the cam and advances with the throttle. I’m sure it’s seated on the cam properly and I don’t think it’s possible to put it on backwards since it has to fit on the notch on the cam in order to advance.

Thanks again for your help, I’ll let you know if I find anything when I go back over the wiring tonight.
 
Also- any idea why the bike would fire if the yellow and blue wires are plugged into the same coil? I’ve been trying to figure it out but I don’t have a clue why that would let the bike start up.
 
Great news!! I went over the wiring this afternoon until I thought I was going to pull my hair out and then I looked at some old pictures of my bike and realized the coils had been swapped by the PO (so the coil on the left side of the frame was actually running to the right plug previously, and vise versa). I swapped the plugs and redid the wiring and she fired up after a couple of tries :D

I'm planning on setting the timing tomorrow since it's still about 45 degrees off when I checked it with my strobe (the pamco site says to set the idle to 1,000 rpm and rotate the pamco plate until the timing mark aligns with the stator). I'll update this if I have any other problems.

As always, thank you so much for your help sonreir!
 
So when I went back the next morning to set the timing the bike was back to not firing :mad:

Rechecked the wiring and everything was how I left it. Connections are secure and I'm confident everything is wired correctly since I had the bike successfully firing with the wires the way they are. Also, using my timing strobe, I can see that the left spark plug is firing when the LF is aligned with the stator notch, and I've verified spark by laying the plug on the side of the engine.

One thing I noticed is that when I pull the left plug it looked brand new and doesn't smell of gas at all, but the right plug looked black and smelled of gas. I'm thinking that the bike was firing on the right cylinder only and the left must have a carb/fuel delivery issue.

I pulled the carbs today and cleaned them. The bike has vm32's which I know are way too big but I was hoping to get the bike running before I put my new vm28's on.

I have a couple of questions that are confusing me...

1. Could the starter motor have gone bad? I replaced the starter motor about 3 weeks ago but I'm worried I've damaged the replacement since the bike was wired to fire 180 degrees off for a while. I think if the starter motor was the only issue I should be able to kick start the bike but when I try to kick start it makes the same "wheezing" noise.

2. Should I just go ahead and put the vm28's on and replace the vm32's, hoping that fixes the left side fuel delivery issue? I'm honestly at a loss for why fuel isn't getting into the left cylinder. I know gas is going from tank -> carb because the carbs were full when I pulled them, and i know the floats are working properly since I checked them too. Is there anything else I can check to make sure fuel is getting into the left cylinder?

3. Should I be able to check the right side timing with my strobe using the same technique as the left side timing? I tried to just hook the strobe up to the right side spark plug cable and look for firing at the F mark today, but the strobe flash was intermittent. This makes me think I have a fuel delivery issue on the left side and some sort of short in the wiring to the right side.

Thanks again for everyones help. I'm really hoping to get this fixed myself, just getting to my wit's end with this project...
 
Are you checking the timing with the points cover on or off? Have you checked to make sure you're not shorting the right side points out? Intermittent strobe suggests you are not getting consistent spark.
 
Hey Irk thanks for your help. I'm checking the strobe with the points cover off, so I don't think the wires are shorting on the cover. It's possible there could be a short on the black/white wire coming from the right coil (it's got a loose connection to the left coil black/white wire) but I've tried to secure it as best as I can. When I pulled the right side plug I'm getting a consistent spark with the plug resting on the engine.

Is there anywhere else you can think of I should check for a short?

Any ideas on why I'm getting no fuel to the left sided cylinder? I tried spraying some engine start fluid in the left cylinder but I'm still not getting ignition, and when I pulled the plug after trying to start a few times the plug looked clean.
 
Thank you for your help Sonreir. I have mikuni vm32s on right now. My understanding is that the only way to sync is to make sure the diaphragms are open the same distance with no throttle, is there another way I should be syncing them?
 
You actually pull the throttle all the way open and make sure the slides are in the same position at the top of the venturi. You can also us a flow meter on the mouth of the carbs, though I haven't done this with a VM.
 
Great thanks for the help irk. I’ve never used a flow meter so I’ll stick with the wide open throttle method. I’ll make sure the carbs are synced today and I’m planning on trying to put the points back on if I still can’t get the pamco to work. I also pulled the left side cover and confirmed the starter motor is still good so that’s one less variable to worry about.

Thanks for all of your help, I really appreciate it.
 
The reason a flow meter is good is because, unless your cylinders are exactly the same, you have different vacuum on each cylinder. You adjust the slides to match the flow of air. The way I described doesn't match it for running operation. It's only a way to bench sync.

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Ok I unplugged the pamco and installed my old advancer and mechanical points. I've hooked the yellow and blue wires from the points to the coils and I'm having a problem setting the static timing.

When I take my test light and hook the alligator clamp to the small pin on the bottom breaker arm and ground to the frame or negative terminal of the battery, the test light comes on.

The problem is whether I manually open or close the points, the test light stays on. It's doing the same thing on both the left and right side. No matter how far open or how tightly I close the points, the light stays on.

I'm assuming this means the points are not properly grounded but I'm at a loss as to where to check. I can see the green ground wire from the harness and its grounded to the frame behind the left points. I added a second ground wire for the pamco unit behind the green wire but I've unplugged the pamco from it so it's just a bare bullet terminal not touching anything.

Any ideas what I'm doing wrong? Thanks again for eveyrone's help.
 
It's sounds like the opposite problem, to me. The points are grounded, but shouldn't be. Usually the points springs are isolated from the backing plate using plastic washers. It's when the points close that they become grounded. Opening the points ungrounds the input circuit from the ignition coils and that's what creates the spark.
 
Ok that makes sense. So should I take apart the points springs and make sure the plastic washer is in tact? I was planning on trying to clean the point contacts and make sure there is good contact between them this afternoon. Yesterday I lightly sanded the contacts with 250 grit sandpaper so there could be some residue preventing current flow. Is there anything else I should check?
 
If you have a multimeter, set it to read continuity or resistance. Rotate the engine until one of the points is open. Then measure resistance between the points spring and the backing plate. You should get no continuity (often shown as OL on the meter).
 
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