Intermittent ignition woes

[49er]

I fitted the 850 with a Boyer Bransden electronic ignition 3 years ago. It has performed extremely well but in recent months I have experienced complete ignition failures during rides.

Last weekend over a 200 km ride, the ignition died 4 times out, and 4 times on the return trip. When this happens, I return the key to the off position and then to the start position and it fires straight up. There is no missing of the engine, prior to these happenings, just a sudden loss of spark. There is no warning and the gap between loss of spark varies. I am worried that I will reach a stage when it won't restart and will need picking on on a trailer.

I have no difficulties starting the engine, hot or cold and it runs like a scolded cat. The ignition switch was replaced last week with a NOS unit. The problem persists.

I was thinking that a loose wire or bad fuse would cause starting issues or even engine missing during operation, but neither of these symptoms are evident.

Am I overlooking the obvious? I do suspect the electronic ignition, but I may be on the wrong track. Any other areas to look at?

[propflux01]

What else is dying besides the engine? headlight? Mine had an almost eerily similar problem on a trip. Turned out the 8-wire connector that goes into the fuse box had one of the connectors corroded to almost nothing. the others were fine, but it intermittently just shutdown and by wiggling the ignition switch it would 'magically' start working again for a while. I replaced the metal contact in the connector, and haven't had an issue in 3 years now. The way I found it, was when it acted up, I just started wiggling every connection I could get to. when I wiggled the connector into the fuse box. it would giggle on and off, so I knew I found my culprit.

[49er]

What else is dying besides the engine? headlight? Mine had an almost eerily similar problem on a trip. Turned out the 8-wire connector that goes into the fuse box had one of the connectors corroded to almost nothing. the others were fine, but it intermittently just shutdown and by wiggling the ignition switch it would 'magically' start working again for a while. I replaced the metal contact in the connector, and haven't had an issue in 3 years now. The way I found it, was when it acted up, I just started wiggling every connection I could get to. when I wiggled the connector into the fuse box. it would giggle on and off, so I knew I found my culprit.

Thanks for the suggestion. I had checked the fuse box and all the fuse holders looked clean and corrosion free. I didn't remove the assy to check the rear of it where the wires connect though, I'll do that next.

I rang a tech rep at Boyer Bransden last night. He suggested that I might have a faulty 5000 ohm resistive suppressed plug cap on a lead. Apparently this can cause the micro processor to shut down. He also suggested checking that all the HT leads were properly secured at the coils. If a spark jumps there it can also cause the processor to shut down. Some of these hybrid electronic systems seem to be quite sensitive to their electrical surroundings.

At least I've now got some direction, so thanks for the input. I'll let you know what I find.

[KiwiGS]

A friend has a BB ignition on his trumpy, he was having similar issues.
Traced it back to one of the HT leads breaking down.
Cheers
*Edit* I see you are on a similar tack, that is what happens when you are half way through answering and the kids need breakie.

[49er]

A friend has a BB ignition on his trumpy, he was having similar issues.
Traced it back to one of the HT leads breaking down.
Cheers
*Edit* I see you are on a similar tack, that is what happens when you are half way through answering and the kids need breakie.

Thanks for your input Shane.

I'm about to remove the tank to check out the HT connections at the coils. I've done a bit of work around that area over recent months, so I may have disturbed/dislodged one of the leads. The new BB coils now hang inside the frame to protect their lighter mounts. Every things a bit tighter for clearance in that region as a result.

[lucabond]

Have you check the output of your RR to see what voltage its putting out ?
I have a dyna ignition that was doing the same thing turns out my voltage would get to high as the reves came up and the computer would shut off to save it from being damaged from the high voltage. Turned out my RR was bad and wasnt regulating so I would get over 15 volts and it would shut down. Good luck

[chef1366]

What's you're resistance on the crank coils with the trigger pointing away from them?
Does these ignitions use a box?

[49er]

Have you check the output of your RR to see what voltage its putting out ?
I have a dyna ignition that was doing the same thing turns out my voltage would get to high as the reves came up and the computer would shut off to save it from being damaged from the high voltage. Turned out my RR was bad and wasnt regulating so I would get over 15 volts and it would shut down. Good luck

No I haven't checked the R/R unit for output. I haven't had any obvious under or overcharging issues such as batteries going flat or bulbs /fuses blowing. I doubt that this is the problem, but thanks for thought.

I pulled the tank and found the #1 coil HT wire wasn't fully connecting with the coil contact pin. The BB kit supplies decent rubber boots that make it difficult to tell how far into the pin the HT wire has gone. I re-checked the others and all were snug fitting.

Next I checked the suppressor plugs and leads. They all checked out at slightly over 5000 ohms.

I did a road test of some 30 kms without the engine cutting out, so maybe I've fixed the cause!!! Not crowing just yet. I've got a decent ride of over 500 kms to do next weekend, so that should tell me one way or the other.
Thanks for the help guys.

KiwiGS, looks like you were right on the mark.

Chef1366, I don't know what those readings are? I won't test them unless I continue to have this problem. The BB system has a micro power digital ignition and it has a processor box I've mounted under the tank. It's a tidy, compact, well performing unit.