No Spark on Boyer - Fixed

hobot said:

If there is any chance you might encounter some Gravel, please a fix video to keep the entertainment going.

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Considering my trials and MX "experience" I'm not terrible worried about gravel. Of course I'll not be going 160mph around blind corners in a place heavily populated with free-range goats either. :mrgreen:

Here are pictures of the waveform taken from a Sachse ignition. The most notable difference is that the Sachse limits the dwell time to 5 milli seconds compared to a Boyer which has a variable dwell time equal to 360 degrees of engine rotation minus the time it takes to produce a spark. Limiting the dwell means the Sachse ignition takes less current than comparable ignitions.

On these pictures, the dwell is seen by the trace going close to 0 volts for the previously mentionned 5 milli seconds





On this picture, it is easy to see the voltage spike induced in the primary of the coil. The spike has a very fast rise time and goes to about 400 volts, so with a coil having a 100:1 turns ratio, the output voltage should reach 40,000 volts.



On the Sachse ignition, the meter voltage readings would not be the same as they would be on a Boyer because of the fixed 5 ms dwell. Taking a reading while running should yield a voltage closer to 12 volts than it would be to zero which is the opposite of what a Boyer would read. The Boyer would be at zero most of the time so it should read zero or close to that.

The voltage measurements are:
running 10 volts
turn on 1.5 volts
after a few seconds of inactivity, 12 volts

Paul I had to ask privately what SwooherooDave found wrong as he just sort a skimmed past the solution to show us a nice sounding steady delight. It was exactly as I and a few others posted - bad connection in the Boyer white ground wire where it hooked to a black +earth lead return lead.

Revealing voltage traces, thanks. Looks pretty clean w/o much lingering ringing.
Would be more interesting to see what varying the plug gap does under full compression.

Swooh I don't have the life time innate bike history most everyone else does.
So if are Gravel trained then you are beyond race track trained except for the aerodynamics effects on handling. Main danger to us all from gravel is going very slow, like walking speed and applying a bit of brake while the tire is not perfectly straight ahead SPLAT before you know what happened. Of course committing to a blind turn w/o knowing what lies ahead and being leaned on patches of grease-sand-grit-grave-blood-guts-gas-diesel-hay-grass-plywood sheet-tangles of baling cords-mud-leaves-trains of caterpillars-box of nails-screw spilled.

To confuse-clarify your minds and hearts- hobot has never ever crashed taking turn at max rates, I've 2 crashes by unexpected extreme wheelies on Combat and Ninja going straight head, very serious damage-injury, but all the rest have been minding my own business and taking good care when a crisis hits. It'd take pages of what I've learned can take a bike-pilot down no fault of their own. It'd take pages to describe what it took to save crashing in flash in the face crisis.
I just hope you don't get the crap that's hit me or caught me out when feeling perfectly safe at ease taking no risks enjoying being alive on a motorcycle YIKES!

Jeandr said:

Here are pictures of the waveform taken from a Sachse ignition.

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I can't even make a decent wiring harness and you throw this voodoo at me? Holy hamburger! :mrgreen:

hobot said:

Paul I had to ask privately what SwooherooDave found wrong as he just sort a skimmed past the solution to show us a nice sounding steady delight. It was exactly as I and a few others posted - bad connection in the Boyer white ground wire where it hooked to a black +earth lead return lead.

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Here's the suspect (the blue connector in the upper left), as I've already said. All the traditional Boyer troubleshooting indicated the stator plate. Because the coil sparked when I touched the two trigger wires together I assumed that the Boyer had to be grounded correctly. Who wouldn't have?

As for hobot pointing out the exact problem, well, it doesn't count after the fact. :roll:

Well Dave, back on page three of this thread I did point to this. And so now it turns out. “Seems to have been Ground wire on Boyer with a bad connection." Not after the fact, page three. Sometimes we just ignore the answer for a while. Glad you found it and it couldn't be a more common cause and therefore a good lesson for all. As I said the directions for negative earth have a mistake in the ground circuit on one set I have seen.

norbsa48503 said:

Well Dave, back on page three of this thread I did point to this. And so now it turns out. “Seems to have been Ground wire on Boyer with a bad connection." Not after the fact, page three. Sometimes we just ignore the answer for a while. Glad you found it and it couldn't be a more common cause and therefore a good lesson for all. As I said the directions for negative earth have a mistake in the ground circuit on one set I have seen.

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Any idea if those directions are posted and/or where did they come from?

From page 3

norbsa48503 said:

Dave, All things that use power must have a pathway in copper back to the battery. The list and therefore the ring connectors are numerous. You don’t want all those ring connectors on your battery because they will tarnish quickly. So we bring all the grounds back to a common ground on the frame and then run one heavy wire from that common point to the battery ground. The Boyer, the PODtronics, the head of the engine and the coils are at the top of the list but the head and tail light , horn also need the ground and any relays you have used as well. I have found a mistake in the directions for a negative ground system on some old Boyer instructions can you find the problem, it has to do with grounds. Think though each one listed here and make sure you are not using the frame for any grounds.

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All you've pointed out is that everything electrical needs a ground :roll: , but no mention of how to troubleshoot a bad ground on the Boyer. Did anyone actually point out how to do that, especially since the Boyer fired when the two trigger wires were touched together or when the kill switch was pressed? How did it do that with an apparently bad ground? Because if someone can't that means that the ground was NOT the issue and there is a voodoo curse that will need to be reconciled.

Before I found my bad ground I too did all the tests and all came back as the Boyer was working. The clue I got was when both plugs were installed the left would not fire, when I disconnected the right the left fired fine so my guess was there was only enought current passing from the Boyer back to the battery for one coil to fire. So I then checked all the connections and wires and all showed low resistance so I finally decided to replace all the wires one by one, just replaced the earths first and tested by luck before replacing any more.

Needs a copper wire back to the battery it’s a big difference. Learn your own lesson is all I am saying. You want to do good for all others with this problem right? I pointed right to the problem because I have learned that lesson and relearned it many times. Wire a chopper sometime were every wire is considered a detriment to the looks of the bike. Same rules applied as your job but just down to just what is needed.

Personally, other than grouding hightlight, instrument lights and indicators, I LIKE using the frame as a common ground. The reason you don't want front end stuff grounded through the frame is that you're basically getting your path to ground through the steering bearings.

So, I run one heavy wire from the common headlight shell ground point back to the main harness ground point at the frame (which also has a single heavy wire to the engine).

NEVER forget grounding Mark IIIs with a cable from engine to battery, as close to the starter as possible, for the starter's ground path. Neglecting that will "highlight" all of your other ground wires suprisingly quickly!

swooshdave said:

All you've pointed out is that everything electrical needs a ground :roll: , but no mention of how to troubleshoot a bad ground on the Boyer. Did anyone actually point out how to do that, especially since the Boyer fired when the two trigger wires were touched together or when the kill switch was pressed? How did it do that with an apparently bad ground? Because if someone can't that means that the ground was NOT the issue and there is a voodoo curse that will need to be reconciled.

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Dave,

Don't feel bad about not finding the bad ground. Everyone kind of pointed to that as a possibility, but did not mention which connection failed. We all learn the check everything twice by making mistakes (sometimes more than once). I had the auto advance and the points plate installed (by the side of the highway in Lethbridge Alberta) when the Boyer ground wire came apart in my hand. I had checked the grounds with an ohm meter and they checked good (even going through the frame). I did not pull on each wire and connector to see it was broken but not seperated. It only took a couple hours and got to meet several friendly Canadians...

Greg

Aw Dave, its all good enjoying the banter before we rot away. Very impressed with your stick-to-it-ness and absorbing as much as I can from your vigor before I soon take on another pensive engine redo. I jerked your leash a bit but hey turn about is fair play. I just hope I only get half the show stoppers you did - going by my past events. I've also been caught out thinking I've already checked the obvious being pointed out to me. Until you revealed ground fault all evidence said badBoyer.
Can take ~1000 miles shake down to track down bad connections d/t poor support or too much tension or shoe elves nibble under insulation or brand new items fool ya.

One of the most pleasing and important Commando features and riding habits to me is all the slowing fast and efficient up before blinds but not having to down shift like most moderns to pull right back to cruise w/o distrubing my smooth flying trance. I also just love to listen to mine at slow idle in back ground while doing a chore, its just so hard to shut that off. Get to the first vintage rally you can if not already. Its like heavenly music all around all day long. Its all new to me you see.

In the analogue telecoms business they have saying when there is no transmission and it's nearly always right (99% of the time) it's either and earth a short or a dis
:lol: :wink: many thanks for the entertainment