[Flicker]

Hi,

Might be a bit late for you but Norton Owners Club of NSW - How to Rebuild a Lucas ignition Switch to Better than New


Tip I was given years ago by another high-mileage T160 owner (same switch) is to drill a small hole in the terminals end at what's the lowest point when the switch is mounted, any water that does get in will drain straight out instead of swilling around corroding the contacts.

There are also some parts that'll make it more waterproof:-

. When Norton fitted the switch on Commandos, they fitted a boot over the terminals end - 06-4891 or 06-5723.

. '81-on twins covered the key end of the switch with a clip-over cap - 60-7335, corresponding switch securing "Nut" is 97-7120.

. T160, '79/'80 twins "Cover" is 60-4335, corresponding "Nut" is 97-4589.


Mmmm ... sort-of ...

The Zener shouldn't "conduct" at all 'til the DC system reaches a little under 13V. You might be able measure "battery voltage across zener terminal and earth" but, engine not running, the two sides of the Zener circuit won't be connected.

Otoh, "10 volts and falling" meant the Zener was conducting, although the engine wasn't running - ultimate worst-case, the Zener conducts without any resistance and the fuse blows.

Hth.

Regards,

Thanks Stuart,
I appreciate the suggestions and I was thinking to myself "Surely there must be some switch out there better than this one"
I tested the Zener diode in an isolated circuit and it holds 13 volts from my battery direct.
So I’m attributing the voltage drop observed in first test to be caused by the intermittent short in the old wiring harness.
And the short must be something like the insulation being rubbed very thin for my fuse not to have blown
With that, I’ll go back to the original electronic components for now and leave the Podtronics for when I might need it.
Also, with the original components in place, I'll have a clear-cut landing point for each terminal on the new harness.

 

[StuartMac]

Hi,

The other component 'leaking' might be the rectifier?

Hth.

Regards,

 

[Flicker]

Hi,

The other component 'leaking' might be the rectifier?

Hth.

Regards,

Could be, I'll test it.
But when I did my wiring harness test, I disconnected every component from it.
So clearly there's got to be a voltage drop across wherever it's shorting.
Thanks!

 

[iainb333]

New carb came in, she downright purdy
Checked all the components to be correct: 230 Main Jet, 106 Needle Jet, 3 ½ Slide

I'd be interested to know where you sourced a whole new 930/60 carb. I think I have sorted my old one with some cleaning and maintenance, but when I looked for a new 'Prom' replacement everywhere seemed to be sold out.

 

[iainb333]

Torqued the head and rocker box bolts, set my tappets to .004 and .006, checked compression to be ~140 both sides.

All the Triumph books I have say .002 and .004. I know you are super precise in all your adjustments and calculations, so I wondered why you used these values?

 

[iainb333]

when I looked for a new 'Prom' replacement

Thanks spellchecker - I meant 'Prem' i.e. Premier

 

[Flicker]

I'd be interested to know where you sourced a whole new 930/60 carb. I think I have sorted my old one with some cleaning and maintenance, but when I looked for a new 'Prom' replacement everywhere seemed to be sold out.

Hi Iain,
I got mine from Lowbrow Customs. The Bonneville shop has them too.
Some other places have them, but with a #3 slide. Original spec is #3 1/2

 

[Flicker]

All the Triumph books I have say .002 and .004. I know you are super precise in all your adjustments and calculations, so I wondered why you used these values?

On an old engine that hasn't been active for awhile, there may occur some "seating in" as it runs during break-in.
If the valves become better seated, that will take up lash and close the tappet gap, so the .004 and .006 is an insurance policy.
If the valve train has no play and the valves get held open during ignition that's bad news.
I also read somewhere that Triumph amended the spec for valve clearance to .004 and .006 in a later addendum but I haven't seen it.
I learned this not too long ago exactly how you are by asking questions on these websites, so I hope I have stated all of this accurately and if not, I'd welcome somebody correcting me.

 

[Flicker]

It’s relatively cold here in Michigan, that’s why (coupled with the fact that I’m no spring chicken anymore) I’ve got windshields on my bikes.
This morning June 9, its 56F (12C?), but the payoff is that this time of year everything is blazing to life after the cold season.
This vine popped up in my brother’s yard and I have no idea what it is, but wow.
Now that’s country
(1711) Marty Stuart - Now That's Country - YouTube

 

[newsh]

It’s relatively cold here in Michigan, that’s why (coupled with the fact that I’m no spring chicken anymore) I’ve got windshields on my bikes.
This morning June 9, its 56F (12C?), but the payoff is that this time of year everything is blazing to life after the cold season.
This vine popped up in my brother’s yard and I have no idea what it is, but wow.
Now that’s country
(1711) Marty Stuart - Now That's Country - YouTube
View attachment 786678

Some kind of Clematis I reckon, lovely.

 

[Flicker]

Finished wiring harness and again was delighted with the quality of the replacement harness. (Stock# MC28 PB and MC28 H PB)
Separate harness for the headlight is a great idea because that is the one enduring the most bending.
I took my time and let the harness tell me where it wanted to go.
The headlight harness that was on there was, in my opinion, routed incorrectly.
They had the leg that goes to the front brake switch jammed through both grommets in back of the steering head and that’s exactly where it failed.
It told me it didn’t want to go that way even before I knew that’s where the fault was.
Left it totally out of the grommets and just fed it from the back of the headlight.

Took the horn off to clean it and found that with it off I had a lot more wiggle room to tidy my wire routing.
There were some damaged connector sockets, typically broken, but I have a small stock on hand.
Took each bullet connector socket off, inspected, and ran a Q tip through with some Corrosion X
(1740) CorrosionX technology and applications - YouTube

 

[Flicker]

Other than 50 years of aging, my autopsy on old harness revealed only one fault.
This is the hot wire on the harness leg going to the front brake switch.
Left of the battery, acid had eaten away the cloth, and somebody electrical taped it, but no wires were compromised.
Chafing on the cloth where it exits the air filter box and under the tank, so I’ll be mindful of those areas.
Cut the cloth off the entire harness and I now have a boatload of British color-coded wire on hand, inheritable by some lucky young family member.
Note to self: Work the Exacto knife away from your other fingers

 

[Flicker]

I came across this cool webpage and in it is a great visual reference on High vs. Low Oil Frames from the 71-72 era
Terry Macdonald (triumphbonneville120.co.uk)

 

[Flicker]

Finished up the headlight harness using Part# 54524048 headlight boot, which is not in my Replacement Parts Catalog, but Mr. Klempf sorted me out.
As I mentioned, my bike’s existing headlamp harness was routed the wrong way and I suspect this was the reason it failed.
Figured out the business end of the harness as well as the front brake switch leg both go through the big hole and the front brake leg comes out the small one.

Wire bundle should be biased toward the right as you’re looking into the headlamp in order to clear the +Common lug on the bulb holder.
A couple of zip ties provide strain relief and held the right bias nicely.

I also made a giant Q-tip with a plastic rod and rolled up paper towel taped to it to clean up inside the glass which was quite dirty.

 

[Flicker]

Put everything back together.
New clutch cable made a big difference. I’ll have to get throttle and choke cables as well.
83-5161 carb boot came in which is for the low frame 72 model.
Picture shows high frame boot on the left and low frame right
I’ve got to say getting that air box back together with the new carb boot was far more frustrating than rebuilding the gearbox, but after several runs at it I figured out the magical sequence.

Started the bike and went for a spin up and down the road.
It ran, but still needs ignition looked at (which has gotten zero attention thus far)

 

[Flicker]

Performed an amperage draw survey and here are the results:
I’m using LED head and tail lamps and incandescent everything else.

Ignition off: 0mA
Ignition on, both coils open circuit: 100mA (oil pressure lamp)
Ignition on, both coils energized: 8A
Coils open:
Switch CCW –Pilot and Tail only: 745mA
Switch 2 clicks CW – Ignition, Pilot and Tail only: 855mA, w/brake: 970mA
Switch 2 clicks CW – Low Beam: 1.29A
Switch 2 clicks CW- High Beam: 1.37A
Everything and Blinkers: 5A intermittent peak

 

[Flicker]

Opened up the contact breaker cover and it was filthy in there.
Removed the breaker mount plate and installed new points.
Upon re-assembly, noted auto advance unit was not springing back to retarded position if the nylon cam follower foot was touching.
Removed auto advance unit, disassembled and cleaned.
Upon re-assembly it seemed better, but still not enough spring tension to snap back under load.
Now I suppose I could fix this with replacement springs, maybe even stronger springs to increase the RPM at which full advance is achieved, but as it is, I am quite busy with the rest of my life so that experiment will have to wait.
I bought an electronic ignition unit and two 6-volt coils that should arrive in a few days.
There are very good arguments on both sides of the mechanical ignition vs. electronic discussion that I’m sure we’ve all heard, and I have to say that I agree with both sides.
I’ll make a nice archive container, labeled for this bike so that if someday somebody wants to make a museum piece out of it, they’ll have the appropriate parts.
I think most of us regard ourselves as conservators of something special, so it’s the right thing to do.
But on the other hand, I didn’t buy this bike to look at it.
The bike already has an AGM battery and LED bulbs, so an electronic ignition it is.

 

[Flicker]

It’s been a while since I added to this because I had some decisions to make about how to approach the electronic ignition.
With the exception of worn-out auto advance springs every component in the old ignition seemed fine after I got rid of the old harness.
I did find some auto advance springs and ordered 4 sets just to have on hand.

However, I always hated the setup under the seat on this bike.
I learned to hate it because that tool tray adjacent to the battery/electronics would sometimes let tools escape and the subsequent smoke from under the seat was always unsettling.
Now bear in mind, almost 50 years ago when I was riding it, it was not uncommon for me to ride it through the woods, orchards, etc. as well as down the freeway at a hundred, all this to say that if Triumph wanted the ideal test rider, I was the guy. You might also say if they wanted to idiot-proof something, I was your idiot.

So I wanted to get rid of the tool tray and make room for an electronic components module with everything neatly arranged, including a panel-mount fuse.
I had some 18 ga. sheet metal with a bend already in it (buss-duct cover) that I sawed into shape for the panel and made a couple coil hangers out of the same stock.
And using 1/8 and 1/16 aluminum stock from the hardware store I made my bracketry.

I ended up with a Vape ignition because to me it looked the most robust.
I chose a Podtronics 3 phase 240 watt reg-rec.
Even though I have the standard stator (2 wire) it will still work and if someday I have a 3 phase it’s ready. It was only like ten bucks more.

Also, since I was unbolting everything down there, it was an ideal opportunity to rubber mount the rear fender.
Every other salient feature on this bike is rubber mounted, and back in the day my rear fender cracked in multiple places.
Again I wasn’t a gentle rider, but to me the hard mounting of this fender is a clear design flaw.

 

[newsh]

It’s been a while since I added to this because I had some decisions to make about how to approach the electronic ignition.
With the exception of worn-out auto advance springs every component in the old ignition seemed fine after I got rid of the old harness.
I did find some auto advance springs and ordered 4 sets just to have on hand.

However, I always hated the setup under the seat on this bike.
I learned to hate it because that tool tray adjacent to the battery/electronics would sometimes let tools escape and the subsequent smoke from under the seat was always unsettling.
Now bear in mind, almost 50 years ago when I was riding it, it was not uncommon for me to ride it through the woods, orchards, etc. as well as down the freeway at a hundred, all this to say that if Triumph wanted the ideal test rider, I was the guy. You might also say if they wanted to idiot-proof something, I was your idiot.

So I wanted to get rid of the tool tray and make room for an electronic components module with everything neatly arranged, including a panel-mount fuse.
I had some 18 ga. sheet metal with a bend already in it (buss-duct cover) that I sawed into shape for the panel and made a couple coil hangers out of the same stock.
And using 1/8 and 1/16 aluminum stock from the hardware store I made my bracketry.

I ended up with a Vape ignition because to me it looked the most robust.
I chose a Podtronics 3 phase 240 watt reg-rec.
Even though I have the standard stator (2 wire) it will still work and if someday I have a 3 phase it’s ready. It was only like ten bucks more.

Also, since I was unbolting everything down there, it was an ideal opportunity to rubber mount the rear fender.
Every other salient feature on this bike is rubber mounted, and back in the day my rear fender cracked in multiple places.
Again I wasn’t a gentle rider, but to me the hard mounting of this fender is a clear design flaw.
View attachment 789207 View attachment 789206 View attachment 789208

Very tidy!

 

[Flicker]

Before and after photos of the under-seat area
Did some poking around for mounting hardware and found:
1/16 x ¼ x 1 ¼ rubber fender washers: https://www.amazon.com/dp/B09T8YJQWC
1/4" stainless bonded neoprene washers: https://www.amazon.com/dp/B076CRK3BZ
Taillight edge trim: https://www.amazon.com/dp/B07DCF3KQ1
I love those stainless bonded neoprenes.
They distribute the stress inside the fender well and also act as a belleville washer.
Now the fender is mounted in a rubber sandwich