Motorcycle Electrical System Rebuild From Scratch

Researched links on re-wiring the 1971 Triumph Bonneville... 

The old Bonnie has an intact loom and many of the original electrical components, but many of these pieces won't have weathered the decades well and I'd be crazy to try and rebuild a hacked on electrical system in a fifty year old bike, so it's all coming out.  I'm going to take a page from the custom scene and build a loom from scratch and design and build a complete electrical system from scratch.

This ain't no modern digital machine so the electrical system in it is prehistorically simple.  Building a dependable replacement with quality modern upgrades (proper copper wiring, modern connectors, new electronic ignition and coils, etc).  The result should be a 1971 Bonneville that is more spritely and dependable than anything that rolled off the line in Meriden in 1971.

Tutorials on creating a motorcycle wiring harness/loom:

BikeExif Tutorial: https://www.bikeexif.com/motorcycle-wiring

Rewiring tutorial:  https://www.liveabout.com/making-a-motorcycle-wiring-harness-743591

Tutorial:  https://purposebuiltmoto.com/motorcycle-electrics-101-re-wiring-your-cafe-racer/

Tutorial: https://www.hagerty.com/media/maintenance-and-tech/building-wiring-harness-from-schematic-to-bundle/

Resource (costs 20 pounds): https://rupesrewires.com/build-your-own-wiring-loom-pdf-book/

Another good resource ($40): https://www.amazon.ca/gp/product/0760345368/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1

I've purchased and read that last one - it's a gentle introduction to electrical work but I found it a bit simple and wished it had picked up speed as it went.  If you've never done any electrical work then it's a good place to start, but that's what I do all day so I was hoping for something with a bit more depth.

Replacement harness:

http://www.britishwiring.com/MC-28-PP-p/mc28pp.htm

Prebuilt '71 Bonneville wiring harness: https://www.thebonnevilleshop.com/product/lucas-71-72-triumph-bsa-650-twins-main-cloth-wiring-harness-pn-54959629-g-99-1222-g/

Original loom wiring colours:

• RED (seems to be earth but then battery + so this is a positive earthed bike?)
• WHITE (headlamp loom)
• GREEN/WHITE STRIPE (LH handlebar switch & main loom)
• BROWN/GREEN STRIPE (headlamp loom)
• BROWN/GREEN STRIPE (headlamp loom)
• WHITE/YELLOW STRIPE (L/H handlebar switch) + ignition coil
• BROWN (headlamp switch)
• GREEN/RED STRIPE (L/H handlebar switch)
• PURPLE (horn press R/H switch)
• LIGHT GREEN (L/H handlebar switch)
• PURPLE/RED (earth?) horn
• BLACK/WHITE STRIPE / BLACK/YELLOW STRIPE (contact breakers)
• BLACK/WHITE STRIPE (condesner pack/ignition coil split)
• RECTIFIER:  WHITE/GREEN STRIPE + GREEN/YELLOW STRIPE+BROWN/BLUE STRIPE+RED (earth)
• IGNITION COIL: BLACK/YELLOW STRIPE to coil & condenser pack + WHITE to coil
• RED (earth frame)
• BROWN/BLUE: Zenor diode
• RED to battery positive (that doesn't make much sense)
• BROWN/BLUE: battery negative
• IGNITION SWITCH:  WHITE+BROWN/BLUE+BROWN/GREEN
• FLASHER UNIT:  WHITE+LIGHT GREEN
• REAR LIGHTS:  BROWN/GREEN STRIPE (rear lamp)+BROWN (stop lamp)+GREEN/WHITE STRIPE (L/H indicator)+GREEN/RED STRIPE (R/H Indicator)+RED (earth)
• STOP SWITCH:  BROWN+WHITE
• STATOR (GREEN/YELLOW STRIPE+WHITE/GREEN STRIPE)

https://monomotorcycles.co.uk/ were advertised in the UK's BIKE Magazine...

https://www.canadiantire.ca/en/pdp/certified-18-awg-25-ft-0207555p.html

The Motogadget is an all-in-one electrical block for all electrical items on a bike - it also provides you with a bluetooth connection so you could start and stop it by your smartphone:

https://www.motogadget.com/shop/en/electrics.html

Not really what I'm looking for for the Bonnie project, though I'll keep it in mind for a future ground up custom build.

A new ignition barrel with keys looks to be about $80.  I'll see if Britcycle has them.

The existing wiring looks like it was taken apart and left that way - I'm tempted to take it all out and just rewire it rather than trust the old mess.

Electrical Systems Parts List:

• Ignition barrel & key set
• wiring to rebuild loom step by step - I'd need correct gauge wiring & connectors
• fuse box
• fuses
• reg/rectifier
• upgraded/modernized stator

Motorcycle wiring how to: https://docs.google.com/document/d/1zm67VyrQTS1_H7WRunfkhOZ1H6wivD6RuK6194P3lvs/edit?usp=sharing  A commonly found writeup someone has done to walk any interested DIYer in how to rewire your bike.

1971 Triumph Bonneville Project: Photos from the current project and long term design ideas

 Some photos from the ongoing 1971 Triumph Bonneville winter project:

One of the boxes of spares.

Spare cylinder head and engine covers.

Looking into the top of the valves...

Yep, that's a 1984 plate sticker on it!

Front wheels cleaned up nicely.

Motor cleaned up well too!

Got it out into the minus ten sun to give it another clean up now that it's stripped.

Strance is back to stock now that the massive chopper front shocks are gone.

The goal is to get it mechanically sorted and ride it rat-bike style next summer to iron out an kinks.  Next winter it'll all come apart again and this time the frame will get painted and so will the body panels.  I've found some year correct Triumph badges but I'm thinking something a bit non-stock for the paint job, like perhaps a Gulf racing livery colour scheme:

https://www.autoevolution.com/news/gulf-racings-iconic-livery-looks-at-home-on-this-modified-yamaha-sr400-149258.html#agal_6

I'm also thinking about seats.  A plain stock seat costs the better part of $500US.  For only $100 more I could get a custom coloured Corbin seat!

https://www.corbin.com/triumph/vintlist.shtml

More research needed, but that looks sharp!  You can customize Corbin vintage seats like their modern bike seats, so I could match it to the Gulf racing colour scheme too.

1971 Triumph Bonneville Restoration: Front Fork Rebuild

It's all snow and wind outside so I spent a good six hours in the garage this weekend rebuilding the front forks and the triple tree on the '71 Bonneville winter project.

The forks on the bike had been 'choppered' with massive fork tubes and spacers in them.  The bike came with new stock fork tubes so after a cleanup both front forks got rebuilt with stock fork tubes.  I'll put the chopper ones up for sale and see if it'll make a dent in the new parts order I got in.

The internals on the forks were in good shape (it has always been stored inside).  After a cleanup they went back together again nicely.  The picture on the right gives you an idea of just how long those fork tubes were (almost as long as the whole shock!).

The right side front fork went right back in no problem, but  the left side one won't fit in the lower triple tree mount (it has a bolt that squeezes it on but the circular clamp is too tight.  I've tried heating it up and wedging a screwdriver in the gap to respread it enough to accept a fork.  I shouldn't complain, this is the only thing that's being difficult on this fifty year old machine so far.

The lower fork unit as it came out of the giant chopper tubes.

The same piece cleaned up.

Parts diagram from the '71 Triumph's parts manual.

Meanwhile, the first parts order came in from British Cycle Parts.  They were great helping me clarify what I needed to get started.  The order was about $450 including shipping and got here quickly (within a week), one box from their Canadian warehouse and the other from their U.S. one.  I haven't started installing anything yet, but I now have what I need to rebuild the Amal carbs, sort out the electrical system and take apart the motor to prep it to run for the first time.

Motor gasket set!

Electronic ignition system and coils!

Amal carburetor rebuild kits!

Rubber bits!  This time 'round I got a new kickstart rubber & the gear shift rubber.

That's a stock style new rubber to replace whatever the f*** was on it.

The monkey who was choppering the bike put massive footpegs on the rear peg position,
but that doesn't make any sense on a chopper (they're usually feet up and forward).
These are the stock footrests.

Stock foot rests (and hardware)!

The plan is to rebuild the carbs, get the motor sorted, install the upgraded ignition system (which I suspect will also involve creating a new electrical loom) and then see if I can get it all to run.  Once I've got it a step closer to running I'll be back in touch with BritCycle to get the other bits and pieces I need to get it rideable.  The plan is still to get it to a place of getting a safety and putting it on the road next season.

I'm not a big fan of lost causes and I wrench to ride, so the point is to get the Bonneville back into service. After watching a lot of Henry Cole on TV, I like the idea of a 'rat bike', which also means I can focus on the mechanics rather than how it looks.  If I can get the mechanics sorted to the point where I can ride it, I'll do a season with it rough but rideable and then consider my options.  I got the bike and spares for $1500 and I've just put another $450 into it.  I think I can get it roadworthy for under $4000 and a non-running barn find bike of similar era was going for a grand more than that a few weeks ago online, so no matter what the Bonnie project won't ever drip red.

In a perfect world I'll get it sorted and some one will offer me more than I've put into it (cost, not time, I'm happy to put time in keeping bikes on the road).  Whether that's once it's roadworthy or once it's been cleaned up too, I'm easy.  Meanwhile the Bonneville is doing what I wanted it to:  giving me an opportunity to go deep on a motorcycle restoration and learn a lot in the process.

The motor's getting cleaned up and recommissioned.

Once the (now stock) forks are back in I'll wheel it out for a deep clean on the motor
and then start with the electrics before rebuilding the carbs.  With any luck the old Bonnie
will be to the point of starting by the new year.

Somewhere in between all this deep surgery, the Concours needs new brake pads and the Tiger has some new sprockets and a chain to install.  To be honest, these minor maintenance jobs are something to look forward to after the deep diving into the restoration project.

Last winter was a deep maintenance round on the Tiger, but even that pales in comparison to the scale and scope of the Bonneville restoration.  Practical Sportsbikes and Classic Bike are both magazines focused on hands-on motorcycle mechanics and both have talked about the dreaded project stallout that can happen when it all gets too much.  I'm taking the advice of both mags and breaking this up into chunks and then solving things subsystem by subsystem.  The small wins help me feel like like the project is progressing and prevent the dreaded project-stallout from being overwhelmed by the whole thing.

On the upside, the fact that we got 15cm of snow over the weekend isn't really on my mind as I'm keeping track of many things-to-do in the garage.

1971 Triumph Bonneville Parts Research

Air Filter Pods for 1971 Triumph Bonneville:

https://www.classicbritishspares.com/products/amal-replacement-air-filters

https://www.ebay.com/itm/382380768469?chn=ps

https://www.speedandsport.com/product/air-filter-vokes-style-for-amal/

https://steadfastcycles.com/collections/amal-carbs?page=2

https://www.knfilters.com/air-filters/universal.html

Electronic Ignition Options

https://www.lowbrowcustoms.com/products/pazon-electronic-ignition-for-triumph-bsa-norton-twin-12v-motorcycles

https://www.motorcycleid.com/1971-triumph-bonneville-t120-ignition-system-parts/

https://meandthismotorcycle.blogspot.com/2010/03/installed-boyer-electronic-ignition.html

http://raskcycle.com/techtip/webdoc16a.html

https://wiringdiagram.2bitboer.com/1971-triumph-650-wiring-diagram/

https://www.classicbritishspares.com/blogs/news/why-you-should-upgrade-to-a-podtronics-regulator-rectifier

Seat:

https://www.classicmotorcyclespares.com/index.php/default/dual-seat-triumph-bonneville-t120-oif-1971-us-spec-suitcase-catch-71-3634.html

50 Year Old Triumph Bonneville Restoration: Amal Carbs and the Fuel Tank

A place where logic, precision and cause and
effect still matter in a world gone mad.

 After the random weirdness of work, time in the garage with the old Bonneville is remarkably
straightforward and logical.  I suspect the bike was in the middle of a Captain America Easy Rider customization in the early/mid eighties when it got parked and time left it behind.  I got it from Brian's storage shipping container where it was out of the weather and raised off the ground.  I don't know where Brian got it from but I suspect it was always stored inside.  I battled with a mid-nineties Kawasaki that had been left outside back in 2014 and this much older machine is nothing like as seized, rusted and difficult to get into.

Anything that doesn't immediately loosen gets a bit of heat and then comes free without any headaches.  Not being in a rush and leaning on the spannering skills I've refreshed over the past decade is making this an enjoyable and meditative process.

The surface rust came off the tank with a bit of sanding.  I'm going to see if I can knock out the dent and then strip it all back.  I used Metal Rescue on the Honda Fireblade tank in my last project and it did a fantastic job of cleaning that unused and rust tank out.  I'll let it sit overnight and then do the power wash tomorrow and hopefully the tank'll come back to me.

The Amal carburetors on the bike are remarkably simple compared to what I've been up against before.  Last time around it was a bank of four last-generation-before-fuel-injection carbs on a '97 Honda Fireblade.  Before that it was a bank-of-four on a '94 Kawasaki GTR1000 and then another complex bank of four on an '81 Yamaha XS1100.  The old Bonnie's single Amal carb per cylinder is a simpler design from a simpler time compared to those complex Japanese four-pot carbs.

Airbox sleeves off.

Carb clean up with a fine wire brush and wd40.

Some aluminum corrosion in the bottom of the carb bowls but it cleaned out nicely.

They've been sitting for a long while, but all the hard parts look to be in good shape.

After an initial cleanup I'm going to break down each carb and clean the hard parts in a ultrasonic cleaning bath before reassembling with new gasketry from British Cycle Supply Co..

Ultrasonic bath bringing the carbs back to clean and ready to breathe for the Bonnie again.

My plan is to get the bike operational mechanically and have it going next spring having cleaned up and rust painted the frame and body.  Once it's operational I'll ride it for a season rough and get to know it before looking to a complete engine rebuild and deeper restoration of frame and body panels at a later date.

In order to get it back to rideable, these are the parts I think I'll need:

• 
  carb gasket rebuild kit x 2
  
• exhaust pipes x2
• mufflers x2
• ignition cables (and possibly some other electrics)
• headlight
• indicators
• battery
• head and sump gaskets for the motor (I intend to go in and clean things out/have a look around before I run it)