Commando dies..

May 22, 2004
Recently as an extension of the post I made regarding the Isolastics and I mentioned I was having additonal problems ~

Some are aware that I was having dramas and had to trailer the Commando on a club ride several weekends back ~ The first trailer ~ breakdown ~ ever..

And of course it took place at the end of the known Universe, in an obscure former mining town Mt Carbine QLD ~ commonly known locally as "Hell's Gate".. a classic western style scene. Mountainous ~ rugged and 37 C. degrees!!

I was enjoying a chase with the fast lot of the Ride , and had backed off after a big squirt in pursuit of a Hayabusa.. (yeah right and I was about to overtake "Graham" on the "bushi" ~

Anyway we all parked at the road house and had 'smoko' ~

Then the commando was dead ~ D.E.A.D.

It had fuel and the spark was present ONLY when I hit the kill button! (?)

And it had heaps of kick/ spark .. occhh!!!

I analysed that the pickup unit was MIA.. and was not delivering the goods at the right moment. (Brand new Boyer kit!!)

Anyway the others pushed on and I sat waiting for Ms M to arrive with Trailer in tow.

Four hours later we were on the way home.

Several days later I pulled it all apart. And I went for the obvious ~

And bingo! ~ I found the cable from the Boyer module thru to the dizzy housing was badly corroded.. (black ) and open circuited !

The bike fired and ran first kick . then stopped again.

I left it for some ten days .. and after some panacea days and R&R on the coast ... I returned to resume.

SO ~ in the end I found that that &*^*&( Lucas multi block connector was a bloody mess... and a number of the bullet connectors were so loose I could not believe that the thing had gone at all in more than just ignition.

So I have replaced the faulty connections and soldered and or tightened all connections
Fires first kick and it runs just fine and I anticipate.. better than ever.. again!!

SO ~ in the end ~ i recommend checking..

The cable to the dizzy housing..

Check all your multi block connections.
Went thru the same problem not to long ago with my 850, like you I redid all my connections, as well I found the kill switch was causing me an intermittant problem. I took the switch cluster apart and cleaned the kill switch contacts, seems to have done the trick. The symptoms were I would be riding along at 70 mph and all of a sudden the engine would die and sputter, then it would go back to normal running.
I have had a problem with the kill switch a couple times, requiring it to be disassembled and cleaned. Measuring across this switch often shows a significant drop in voltage. I have been thinking about wiring in a Bosch-type relay that will energize with the keyswitch, then be de-energized when the trigger circuit is opened by pushing the kill button. This should allow full votage to reach the Boyer as long as the kill button passes sufficient voltage to keep the relay energized. Has anyone tried this?

I am a dead keen fan of relays and cannot recommend them enough .

I agree with your thoughts totally here , in fact would recommend incorporating 'bypassing the ignition switch as well ..

This may just take a little fore thought but is certainly ~ and easily done. (Well .. for me being a former tradesman..)

Your evaluation is spot on ~ In fact I fitted one to my brake lights as the front switch had gone high resistant and as I had a spare relay I fitted it up and the brake lights are perfect. eliminating any resistances..

But in evaluating the original problem here ~ I am of the thought that IF my Commando ~ or any bike DOES not start first strike.. as far as I am concerned there IS SOMETHING WRONG ~~
I agree if the bike doesn't start within a couple kicks, then it needs attention.

My thought on the relay was to route a lead directly from an open circuit on the blade-type fuse block I have installed, to the relay and from the relay to the Boyer. Then the energizing circuit would be routed first through the keyswitch then the kill button to the relay. Is this what you had in mind?
I've already done the relay thing. Piece of cake.

Commando dies..

Mind you, I switched to negative ground - simple enough to picture the reverse (switch red and black in your heads).

I've got the headlight and horn on relays as well, but running straight from the battery - not through the ignition switch. The relay on the ign switch is for the Boyer, gauges, turnsignals, tail and brake lights. "R" is the 20 amp relay, btw. 20 amp relay with only 7+ amps draw max.

I had Jim Bush at Eastern Beaver set me up with the necessary bits.
From your diagram, did you eliminate the kill switch or is it still after the relay?

My scheme is a little different. Main feed from the battery to a common post on a four circuit fuse block. Three fused leads from the block lead to 1) horn 2) headlights 3) ignition with a relay wired between the fuse box and each device. A fourth lead then supplies the voltage to the keyswitch which in turn supplies the ignition relay via the kill button, high and low beam relays via the handlebar switch, and horn relay via the horn button. Therfore only amperage necessary to trigger the relays is drawn by the keyswitch or any of the handlebar switches.
Has anyone ever used an electroconductive paste on bullet connectors?
Just a thought, since it may be easier than soldering everything together.

commando dies

Lots of discussion about relays,what are the specs. for relays used in the circuits, where to purchase etc..
I have ZERO expertise but would like to know more, I would like to add relays if that improves the electrical system -- lighting etc.. Ride safely. James.

I'm using a Baja Designs switch cluster with a kill switch. From my schematic, it looks like it either grounds or interupts the positive side of the ignition coil.

I just broke the motor in on the dyno last month, but the boyer was wired straight to the battery for that exercise - so I haven't tested the kill switch yet. I should have most of the wiring finished this weekend - neatening it up is the bigger challenge.

Might kick it over and test the kill switch then, but I'm having primary belt-drive alignment issues that I'd like to work out before running it much more.

Lots and lots of debugging to do.


A relay is a kind of electrical switch with low internal resistance. Better than putting all your current through a mechanical switch (like the Lucas handlebar unit). Check out for some more details.
Ron L
Again you hit the nail square and fair...

A 30 amp or even 40 amp relay is very appropriate.

DO NOT go trying to get relays any smaller as ~ after some 18 years on the DC electrical trade it is highly inadvisable to go less. The reason being that "not all are created equal"!

The construction is depend on the quality of the contacts. Lesser bits can run a serious risk of damaging, burning or striking the contacts.

I would not aim too hard at getting too tiny a relay.. they do need to breather as it were. The 'standard ' miniature relays are about practical as it can be ~

Circuit breakers are also extremely prone to this.

The difference with a circuit breaker though is that you CANNOT ~ CANNOT exceed the current rating as as Circuit breaker is designed to OPEN at the given current rating.

I personally like circuit breakers as opposed to fuses. There is available argument with these though that they can stick the contacts in a 'short' scenario.
This why you should never consider using cheap circuit breakers.

I don't see how my use of 20amp HD automotive relays is a problem - especially given my use of 15amp blade fuses between them and the battery and 10 amp fuses at the fuse box.

My high beam, low beam and horn are all on seperate 20amp relays and the fourth relay covers everything else. Peak draw on the ingition, etc circuit is 7amps - less than half the relay's rating.

Enlighten me as to the potential problem, please.
commando dies

Thanks for the info. regarding relays, time for some experimenting now, good to know that you guys are out there offering guidance. Ride safely. James.
Oops ~ sorry ~ perhaps I was not precise enough.. I agree 20 amp is fine in my opinion.. the point I was endeavouring to make that regarding relays the higher rating is advisable.. not so rating a relay equal to the current draw ~ more is better..

And Circuit breakers .. have to be exact.. definitely not more is best !
I'm a fan of simplicity. But I also hate pushing motorcycles. My daily rider is a 68 Bonneville opened up to 765cc, five speeded, and fitted with a single (larger) carb....simpler, after all. I never have been a fan of batteries, what with the weight and corrosive fumes, acid splatters and maintenance requirements, not to mention regular expenditures for replacement. I know the new "maintenance free" batteries address a couple of my objections, but I have my prejudices, ya know?
So, my bike has run sans battery for about ten years now. Approximately 80K miles with two primary chain changes, one tappet replaced when it spit the stellite off (only one I have ever seen do this), and I had the rocker boxes off to replace gaskets and orings. Other than that, it has been a real soldier.
I fitted a Lucas three phase alternator and a Tympanium voltage rectifier/regulator, which I mounted up under the headlight for good air flow. I suspect I will replace these with a Sparx three phase unit when/if this craps out. I fitted a new rotor as "permanent magnets" aren't. I use a 4500 mfd capacitor to filter the DC spikes at low engine speeds, but the 3 phase has more closely spaced spikes and they are naturally less of a problem. I am running points and cheapo Taiwan Lucas-replica coils, but will try this with the new Sparx EI system and some Dyna coils, in parallel, not series, soon. I expect it to work just fine without a battery, as it is supposed to be designed to work over a larger voltage range than the Boyer.
I wired the bike with Belden aircraft/milspec.'s silvered and teflon insulated, instead of pvc. I used 16 guage throughout. The insulation of this wire is only 11 thou thick, but withstands an open flame, like a candle or match, for a LONG time with only a bit of soot from the flame to show. The wire solders beautifully and will take a set when bent. It makes very small and tidy harnesses which are more heat and chafe resistant than the conventional wire.
I eliminate the blade connectors wherever possible, such as on the coils, where I solder ring connectors to the wire and use internal serrated washers and conductive grease to seal the joint.
Currently, (no pun intended), I am stalling the engine to kill it, not the best plan, but my cheapo ign. switch failed. I will fit a relay to try that, and get a decent kill button for the handlebar. Since I don't have to switch off a battery, starting is just tickle and boot, like a magneto.
The relay and a properly designed quality switch should give about the same resistance readings when new, the payoff comes with time, as the relay contacts are sealed in a case, but the mechanical switch is usually open to the elements...a problem, particularly as most of the kill buttons are exposed to the elements in a vulnerable position. The Norton and later Triumph/BSA used a series kill, so that the power for the coils has to pass through the handlebar switch to energize the coils, so any loss there results in reduced spark output.
Without a battery, you can also dump the fuses and circuit breakers, since a short will kill the engine....and power output... without melting anything. It also leaves a lot of room under the seat for storage, different oil tank or filter, etc.
I run a halogen headlight, and it is easier to start with the light off, although with a good boot, it will start with the light on. The idle doesn't drop much with the light on, but I have extended adjustment screws, just in case. I recently leaned out the midrange by dropping the needle a half notch, which cleaned up my plugs and made the idle steadier. Better mileage, too, with fuel just now dropping through $3.00 a gallon here.
All in all, it has been a stone reliable, fun to ride way to get around Honolulu, and a few jaunts on the Big Island for Labor Day.
While this is a Triumph, the electrical stuff is the same for Norton or BSA.
More women would appreciate men if Lucas manufactured marital aids.

:lol: :lol: :lol: :lol:

Then the bloody thing would expire before the job was done !!!! ~ leaving all hanging out in darkness ~~ well short of the desired destination!! :( :shock: :twisted: :twisted:

OR ~ worse still only deliver only half the anticipated results.. :lol: :lol: