1968 BSA Thunderbolt 650cc - going home, or NOT (part 2) 

I am the sole surviving family member of the Bsa dealership I was 14 when I went to Bsa service school 7071 the last one they had in the US Nutley New Jersey January 71. You’re missing a seal on the inside of the primary to keep or from leaking all the bike through the hole where the wiring goes looks like a spark plug wire camp, far from perfect but it helped. And Lucas‘s defense, Bsa beat them about the head and shoulders to get the price down to $12.50 for the entire electrical system in the early 60s that included the headlight completeTail light complete battery charging system handlebar switches everything. It’s no wonder they use beeswax for waterproofing.

cracking filming, so clear.

the joy off working on old brits lol,had five tridents got the scars to prove it.

I really love your movies. Make me Peace and calm,and smile!!

Another very helpful video, Mike. I have several electrical issues that popped up. The stator charged but quite. The headlight worked but quit. The horn worked but quit, each at a different time. I suspect the connections are just loose and need to be tightened or the connectors replaced. Watching your video helped. Thanks.

You can't blame Lucas for old, dried out wire insulation. When you look at how long these old British crocks have been around, I'm sure that most of them have long since out-lasted their intended service life. And you sure can't blame Amal for some ham-fisted owner or mechanic over tightening the carb nuts, distorting the carb body. Mikuni carbs are mostly spigot mounted and therefore not vulnerable to that kind of damage, but it doesn't look like there's enough room for a Mikuni conversion on this bike. I converted a 1960 Triumph Tiger Cub, but had to remove the stock airbox to gain the room I needed. it worked great! Easy starting, terrific throttle response, and easy to tune. I recommend the process highly.

Admire your patience ( oh bollocks!!) made me laugh out loud , thanks very entertaining .

I love British bikes but hate working on them and your video brings back some grim memories. In my mind Amal is a synonym for nightmare, Lucas is an invocation of horror. However, I hugely admire your patience and skill. Best wishes for success with this project.

Sorry for the late reply. #1 Troubleshooting the no/low fuel issue. First step should have been to verify that you were getting sufficient good [fresh with no water] fuel to the carb, before removing the carb. #2 the throttle slide, aka piston as you call it, sticks, is because the bore is warped due to over tightening of the mounting nuts. Sanding the flange surface flat does not help repair that. You should have attempted to reduce the warp of the mounting flange using a press to remove part of that warpage, before sanding the flange. That will minimize the slide sticking in it's bore. #3 To get the stator wiring harness through that tight opening , do the following. First heat the stiff wiring with a heat gun or electric hair drier, to soften the insulation. Next, fold back one of the two bullet connectors, then pass the harness the the opening. The idea is to have only one bullet connector pass through the restricted opening at a time. #4 Always stagger any cut off wires, so that the bulge in the harness after repairs is reduced. Placing two "fast on" connectors next to each other is poor workmanship. #5 Slide heat shrink tubing over the wire, BEFORE you crimp on the "fast on" connectors. That will eliminate the need for using electrical tape. Electrical tape will unwind over time due to vibration and oil contamination. Alternately, apply a thin coat of "Liquid 'Lectric Tape, over the electrical tape, to prevent it from unraveling in the future.

A bit of Lubricant would have helped!!!

I’ve found that soldered wire on a bike usually always breaks right next to the solder. Since then I use covered crimp connectors and try to avoid heat shrink tubing as it creates the same situation as solder, reduces flexibility

Try spraying a little WD 40 on the wire to make it slippery and easier to pull through.

Are witworth tools an absolute must for working on the older brit bikes? wouldn't mind having a BSA or Triumph some day

i hope you dont mind me askig but what is / was your day job,

It's a throttle slide not a piston and the needle is held by a circlip!