1 BRIEF STEP AHEAD, 2 STEPS BACK
Fixed the starter voltage drop issue via the diode and capacitor (but only briefly) but now I have no more spark! (and the draw is creeping back to 2 v)
Before Installing the diode and cap. I tried to do a test by inserting a small 12v battery
from a dirt bike where the cap would go. I grounded the POS to the main battery
but the instant I touched the NEG to the connection that connects the dual colored ign wires to the white Boyer
wire the dash lights lit up even though the ign was not turned on. I realized this is bec. I had no diode to prevent backward current. I only tried this 3X for an instant . Would this have ruined the Boyer
box? Apparently not, see last para.
I did not check for spark then, did not occur to me to see if I still had spark.
So I installed the diode and Cap as per Quinten’s instructions : Diode with NEG from the dual colored original feed wires and POS facing twd the Boyer
and then I connected the Cap to the diode with the NEG connected to the diode POS end, and also connected the white Boyer
wire there (a T connection into the Cap NEG end wire). The POS end of the cap I presumably grounded but cannot remember doing so and suspect I forgot.
When I then used the e-starter instead of a 2 v drop across the battery
I only got 1 v drop so Hooray and I soldered in the connections taking care not to apply heat for more than a few secs at a time and using very thin fast melting solder and using a vice grips as a heat sink. Also for the end of the diode that connects to the stock dual colored ign wire I crimped rather than soldered. I attached the cap. POS ground to the engine (maybe that will got too hot if the engine ever runs, I shld ground it to a cooler spot.) I tried the starter and again only a 1 v drop.
Hooray again until I noticed that my test spark plug taped to the head was no longer sparking. ! step ahead and 1 big step back.
So I cut all the soldered connections and removed the diode and Cap and reconnected to the “status quo ante” and now have my spark again so did not ruin the Boyer
I then discharged the Cap and tested it and it still says 5000uF so I used a new diode and the same Cap. (properly grounded) with good but not soldered connections and but still no spark; also its now back to taking 1.7 v instead of 1 at the starter.
But I think Dave Madigan answered all this on Oct. 10 when he wrote:
If that diagram of the Boyer
wiring is what you have then the diode/capacitor idea will not work. I thought the Boyer
timing was powered separately and it switched the coils from the ground side.. Since the Boyer
is switching the coils from the powered (B-) side the timing electronics shares the coil power lead.
The capacitor will not store enough energy to drive the coils when the starter draws down the battery
So it was fun experimenting (the Cap and diodes only cost me $23) and learning more about electronics but seems I am going to have to do like everyone else and spend a small fortune for a Tri-Spark kit when I may be able to afford it.
BUT the big mystery is that two companies that sell e-ignition kits (not just Boyers) say that they have many happy T160 customers using analog Boyers, and my own bike started and ran from 2012 thru 2018 on the old Boyer
Mk III until it gradually failed in 2019. One would assume putting in the new Mk IV would have at least put me back to where I was a few years ago, esp. since then I have replaced a few dodgy wires, installed fatter starter cable, cleaned connections, cleaned the starter, new Odyssey US made battery
, new spark plugs and ensured the HT leads are compatible with the Boyer
, checked coil resistance, new solenoid about 2 years ago, and made sure to my bile follow John Healy’s advice (it already did) that “Alternator wires should never be located near, or run parallel to, the timing plate wires, or battery
ground or feed wires. For example: T160 wiring harness carries the alternator wires in the same wiring sub-harness with the wires coming from the timing plate. etc. Well at least I reduced the draw from 2.0 to 1.7 volts.
The only thing I can think of is maybe previous owner had the coils wired differently than the way shown in the diagrams above as I recall switching a couple of wires last year to make them jibe with the Boyer
diagrams. Be funny if by wrongly linking the coils he was able to make it run.
PS I ordered one of the original blue capacitors (common on most Brit bikes, optional on T160). Just wondering if installing this either with the current failed mods or w/o them will have any effect? Also wondering if they had a built in diode as otherwise what to prevent current going the wrong way?