Bonneville America Forums Forums Technical Forums General Tech no fire right side

Wendy's bike lost fire on the right side. I swapped wires and the right side still had no fire so figured it was the CDI. I replaced that and still no fire on the right side. I know both coils are OK and I made sure it was no spark vs. no gas. Anyone else had this same issue? I'm sure I can track it down just would go to the most likely spot if this is an issue others have had. I tried a new coil on it but no joy there either.

PS. Also made sure the plugs were bogth working on the good side.

When mine did that it was the igniter. Maybe the connections at the igniter harness? Air gap at the pickup coil? (.08mm)

checked all that already, thanx. The other coil has good strong steady spark. I have not been able to find any connections that look less than perfect.

plugged pilot?

Not that either, there is no spark, electrical.

In my case you can bet I already checked all the simple stuff, looking for something electrical that would cause only the right coil to not fire but coil is good and just replaced the CDI. (would have bet that was the problem)

Thanx Bill, I appreciate the help. I have set the pick up coil to the new spec back when it was first recommended to do so. One question about that pick up coil though is, do you know if it would allow a strong steady spark on one side and nothing at all on the other?It runs like it should on the left side and with the plug out of the bike laying on the head to check for spark one side has nice steady blue spark and the other side nothing at all, not even an occasional weak yellow one.

I have to say, with no spark on one side at all and good on the other I was sure it was the CDI.Especially when I swapped the wires and the problem didn't move meaning both coils are OK.Double checked that with the plugs out too.

Still beating my brains out on this one, I reset the pick up coil gap again just in case but still no joy. I doubt the pick up coil is bad since I have good fire on one side.I went through every plug on the bike and all look good.

Hey Ian, did you swap plug wires as well?

I left the pos. wire connected to both coils and only swapped the neg side from the good to the bad and the bad side then fired, would that indicate a bad pick up coil? The CDI is a new procom I just installed. Again I can find nothing wrong with that wire anywhere.

If you have a schematic of the ignition system it should tell you if the pickup has a right and a left circuit. I believe that both fire at the same time, but it could still be a dual setup inside the coil. I have heard of one cylinder dropping out due to a bad adjustment on the pickup, so a bad pickup may cause that also.

I do have the schematic, I'll have to have a look. They are different colors so I am guessing they are individual, both pos. are red and the grounds have a purple stripe on one side and a black stripe on the other. Being 270º I didn't think they would fire at the same time. Is so I would just run a jumper and ride.

Here is the post that Mike shared related to his pickup coil heating up. When it got hot, the bike quit. Cooled down and started. He checked his pickup coil with an old style voltmeter which gave a pulse when a magnet was waved over the coil. I think our flywheels have 2 magnets situated in the appropriate location to give the 270 degree firing pattern. This info might help track down the problem which has me stumped given the fact you switched and replaced pretty well everything.

One other item, I just checked the part number for the pickup coil for the 360 and 270 engines and they are the same telling me that there probably isn't two separate circuits. There are two separate magnets though in the flywheel. Is one of your magnets missing??? Could it have fallen out?

If you changed the CDI unit, coils and the pickup coil/magnets are good then the only other thing I can think of is the harness from the pin-out of the CDI unit to the coil shown in the print. Good luck.

I wasn't sure if the 2 wires out of the pick up coil were part of one circuit or if one was for each side.I really didn't want to open up the harness, pins and wire connections are visible at both ends and are clean. Every plug in the entire bike is clean as new and greased. I couldn't find any rubs anywhere that could cause a short. I have to take a good look at the schematic and maybe I can use a continuity tester to check for a break somewhere.

I had two thoughts, one that the lead from the igniter to the non firing coil is broken and the other was that somehow the Procomm dip switch was set for 360 instead of 270. Did the lack of spark move with the spark coil input?

AFAIK the pickup fires off the stator and the igniter software interprets the pulses and directs them to the appropriate coil. Different stators for the two engines but the same pickup coil. Since the 360 is a single input, dual output coil the igniter would only signal one coil.
Grasping at straws here Ian with a couple of guesses.

Thank Ed, I understand how the ignition works basicly but not what happens inside that little black box.I can see on the schematic the wire that seems to be the problem is a straight shot from CDI to ground side of that coil but I don't know if that is a common ground or 2 different circuits. I am going to go out today with a continuity tester now that I know what the wires are and what they connect to.I hope it is as simple as a broken wire. I am pretty much stumped if it isn't that.

The lack of spark did move with the coil inputs every time.

I was working on other stuff all morning. I just went out with my multimeter and there are no broken wires that I can find.I am really stumped unless the pick up can be bad for only 1 side and still fire the other normally.

Yes, given that one side has spark and you have eliminated the usual culprits I was just out of rational ideas. You have power at the coil input don't you? That would leave that ground path as the last place to check...unless I am just ignoring some basic item.

I took the ground off the side firing and moved it to the side not working and did not move the pos. side and it fired so there is something with the ground on the bad side for sure but can't figure out what unless it is something with that pick up coil. But could that being bad cause only 1 side to malfunction? That's the question.

I don,t know why a bad pickup would booger the ground as it is only sending a small pulse to the igniter. Either the igniter or the wire from it to the coil is your culprit. The Procomm impled the wire was bad. That's where I would look first with your multimeter.

Reluctor(sp?) for the #2(right)cylinder on the flywheel intact?

Yes Chy, flywheel is in perfect condition and everything else down there appears in perfect condition aswell. I wish it was something visual I could see.I'll check the resistance of the pick up coil.I haven't looked at that too closely since the one side fires perfectly.I wonder if it could be a bad CDI from Procom.I checked the numbers on the OE CDI and the Procom should work.

This really has me stumped so I spent most of today running a chainsaw cleaning up some stuff that was in need of trimming or growing where I didn't want it. Popped back to the bike a few times hoping a fresh eye would spot the issue.

I seem to remember the pickup coil in the thread Greg mentioned started at 600ohms but that fell to 0 as it warmed up. The diagnostic test had the coil in a cup of hot water and he watched the impudence collapse as it warmed up. Such a cool idea for a test...

Good idea but this one isn't working dead cold if that is the issue.

Keeps bringing me back to the igniter, or the ground wire from the igniter to that coil. Was the Procomm off your bike?
The grounds to the coils from the igniter are pin 14 and pin 8, that would be a decent place to check continuity and eliminate the wiring harness.

Clutching at straws here...we'll learn something valuable for the whole community when you solve this.

I have continuity at the pick up coil.

Was it 600 ohms?

it was five hundred point something.

I checked the ground wires right after I looked at the schematics to be sure the line didn't connect anywhere else. They both measured the same and had continuity.

The Procom is brand new from Eddy.

You're right Ed, it was 601 ohms across the two leads which confirms that the two leads cannot be two separate circuits, (one for each coil). I think you nailed it when you said "the pickup fires off the stator and the igniter software interprets the pulses and directs them to the appropriate coil". If Pieman was on, he could probably confirm how it actually works on the 270 since he programs them.

Ian, do you have a spare CDI from your other bike you could try? Hope the new Procom isn't defective?

I am afraid of damaging the stock one from my SM since I wouldn't settle for a Procom on my bike.

Ah, you're stuck then without a known good igniter to use as a test. Seems like you have eliminated every other culprit.

Ian, the only other thing in the igniter circuit is the Throttle Position Switch.
I know it's not logical as far as one side not firing but, unplugging it would eliminate it as a cause.
Just throwing it out there.

Thanx Tony, I have been rolling that around in my head but haven't done it, I don't know why.I might do that and swap CDIs today much as I hate to do it.