Seems you are Pained by the unraveling of the Vintage Bikes. Must be a common retort across the Atlantic when buying and restoring to original condition. I see the mind moving possibility's of what was and what will be. Don't get me wrong , you write what you want and that is that. But I see that the problems that are encountered are kind of anguished. I find problems as reason to search a solution with the minds eye to enjoy the ride. No Disrespect. I think bikes are a form of disillusion of the days constraints. I have enjoyed your post but thought to chime in. Cheers Chris in NNJ

Nope you got the wrong end of the stick. I got two bikes done that I rarely have time to ride already.
I do not do this because of the end result, I do it because I enjoy the challenge.

If I didn't, I would not waste my time and money and I most certainly would not have pursued the extremely demanding career I have had for the last 40 years.
Getting sent a pile of rusty parts from somewhere in the world, from a 60 year old piece of heavy equipment, built by a long defunct manufacturer and turning them into a useable driveline again is my bread and butter.
Old bikes are nothing in comparison.
Simply light entertainment done for fun.

As for the impression you have got.

I post in a manner that magnifies my problems and diminishes my successes because that is what people want to read.
No one likes a master of the universe poster that never puts a foot wrong, or should I say his ego never allows him to mention it.

People enjoy my style because it encourages them to continue when many would give in. It offers problems and solutions to others with less experience who are looking in and is a far more entertaining read for all.

My posts are warts and all. I have nothing to prove to anyone where technical matters are concerned, and my long since conquered ego allows me to lay my mistakes wide open to the world without shame.
It is more shameful to be fuelled by ego and posting accordingly.

I stand corrected. And have checked my ego. Chris

Not intended as a pop at you Chris. If you thought that, I am sorry.

Just setting my stall out and explaining why I post as I do

Progress has been slow this week, mainly due to the parts situation.

I envy the US with its huge motorcycle market and consequently a very good supply of restorable bikes and spare parts at reasonable prices (apart from the NOS price scalpers).
In the UK, we never had such a huge market and consequently relatively small stocks of bikes and parts.  This makes  parts almost impossible to find at times, esp on a fairly unpopular bike. 
I bet in 1977, Yamaha UK or  Mitsui machinery sales as it was known then did not sell 50 DT100s.
Add in a US only spec bike and only that spec in 1977 and you get the picture...

Consequently one has to get creative.

The throttle cable was broken in two at the handlebar adjuster, just the inner holding together, so I needed a new throttle cable upper.  The connecting cylinder was also broken.  I found a NoS cylinder in a couple of days of searching and ordered it.
The cable was more problematic.  No trace in the UK and Europe.

I did find one in the US for $150.  Jog on mate, not a chance you charlatan.
I found another in Aussie land for $40 US and  $75 shipping.  Ouch.

Time for aftermarket.  I have covered that sorry tale in a previous post.  Useless.  I could not even strip it for parts as its construction was entirely different.  I was going to have to use my original oil and throttle cables and the new cylinder.

Time to look at other DT100s to see if anything was available that looked even close.  Later models had the same cable as mine, so that was out.  That just left the earlier models.

Closest to original seemed to be the 1976 and I found a NoS one one fleabay.  At £30 it was an expensive gamble.  I already knew the guide elbow was at a different angle, but I was confident it would fit. 

Cable arrived and before fitting it to the throttle tube, fitted the lower cables  into the cylinder and clipped them into the upper cable piston.  Time to clip it together and fit it to the throttle tube.

Piston would not go into the cylinder.  It was about 2mm too big as was the cylinder cap.  .
Also the inner cable was about an inch longer.

Who would have thought it?  Dammandblastit.  Time to get creative. 
Had a good look at the parts and decided the only way was to cut the inner cable to the correct length, fit my old piston and cap, then solder on another nipple.

Not having a nipple, I had some lucar terminals that had a copper tube core inside the crimp section, so I had a new makeshift nipple.  Cut the required section from the terminal, tinned the inner cable, cut it to length, fitted my old parts and crimped, then soldered on my new nipple.

Fitted it to the carb and the twistgrip.  A quick adjustment and we have closed throttle with healthy free play one way and fully open the other.
Yippee.  I can wipe the sweat from my brow now.
Handlebar switch and cable fitted back on bike.

Looks like it was made for the job.


Even got the bend angle sorted without kinking the tube.  Another bullet dodged.  It could have all gone horfibly wrong and often does.  I got lucky.


As mentioned, I straightened the fork tubes, and one of them had five or six rust pits right where the seal sits.  Since the bike is not worth spending the money on having the forks rechromed and new tubes are not available, I had no option but to remedy matters with the old superglue trick.  Should hold for the very small amount of time the bike will be ridden.

The fork lowers were stripped of paint, polished and scoured back to a satin finish before getting four coats of clearcoat.  I think it looks far better than the original silver paint.

So time for assembly.  Oil locks onto damper rods, springs dropped in, upper metals fitted, tubes dropped in and with a cheery whistle, I opened the fork seal and dust cover kit I bought.  Dropped the seal onto the tube and it fell down the tube.
What the feck? 
A look at the seal told the sad tale.  30mm.  The fork legs are 27mm    Ballacks.
Job on hold.

Only other progress is the swingarm and associated hardware have been blasted and painted.

Swingarm and chain guard fitted.  Just noticed those chainguard screws in the pic.  Looks like they need shortening.  I am wondering how easy those shocks will come apart.  I want to blast the springs and repaint.


 

In addition to my earlier comments about the UK market being small.

Here are the official DVLA records for surviving DT100s in a roadworthy condition in the UK.  This is all models from the first year of production to the last year of production for the UK market.

DT100 of all models in roadworthy condition in the UK in 2023 = 25.

Soon to be 26.

www.howmanyleft.co.uk/?q=Dt100&commit=Search



 

Wow... It's also interesting how the link you had up showed in 2021 the numbers of "garaged" and "roadworthy" DT100's both spiked with the roadworthy examples exceeding the garaged for the first time in many years.

It's amazing how few there are.

That time in the rebuild when it all starts coming to life.  Pleasing.  When it arrived, nothing worked.  Of course, the neutral switch is on the motor, so it is "simulated" by running the sky blue wire to ground instead of the switch.


If the wrong forks seals had not been supplied, I would have had the headlamp ears and bucket fitted today.  The handlebars look bent.. They are not, it is just the camera angle.  The speedo is almost six feet above the ground, so my phone was way above my head when I took the pic.

 

Very very slow progress this week.  I sent the orginal incorrectly supplied fork seals back and ordered some showe replacements from a different vendor.
After a week, it transpires that this vendor has engaged the slowest postal service in the UK.  Still no show.  Getting a bit peeved at the wait now.  It is really holding things up.

Meanwhile I tidied the rear shocks up, but could not get the locking collars for the upper spring retainers to loosen at all without damaging something. Solid.  Blasting and spraying the springs was no longer an option.
much wire brushing and rubbing later and I just sprayed rattlecan enamel into the cap and used an artists brush to paint them.  I did spray the spring retainers though.
They did come up OK but no point in taking a pic.  They look like the ones in the other pics only a bit cleaner and shinier.

I had a look at the seized up speedo drive in the brakeplate.  Rusted solid.  Looked like it was stored 40 years ago, full of muddy water.
Removed the oil seal and applied heat as much as I dared. I managed to avoid the brakeplate transforming itself into a mis shapen silver splash on the floor. Bonus.
Still solid.though. 
Cooled down with penetrating oil.  Still solid. Gave the gear a good rattling with hammer and punch on the driving flats on the gear and used an adjustable spanner to try turn it.

Aha! Small movement, but obvious the worm gear was also seized solid.  Gave that a good rattling on the teeth with the tip of a screwdriver blade, then moved the pinion a fraction, then the worm gear, then the pinion....

Eventually freed it off,  dismantled it, cleaned it up and regreased everything with moly grease. Phew.  Pretty intense couple of hours.  Replacement assemblies are like gold dust in the UK.

And we look at my nemesis.  The bodywork.  I am absolutely crap at bodywork.  Made the tank dents a bit better by pushing them out from inside with a tyre lever, but they are going to require filling.  Oh dear.  It is going to end up a mis- shapen wreck.... Filling and shaping dents and cutting wood to size.  Two things I can never do right...


 

Cleaned the front brake hub, removed the bearings, washed out the grease, relubed them with EP2 and refitted them.  I replace wheelbearings as a matter of course usually, but there was nothing wrong with the old and because the bike will never be really sought after, I am on a strict budget this time.

Inflation runs rampant and times are hard. 
To this end , I usually fit new tyres and tubes at the point when I am fettling the wheels, but since it will probably be next year by the time it is registered for the road; I am deferring those to the very last.
The £120 I was going to spend on new tyres and tubes next month will be better spent on parts that will progress the project now.

Wheel fettled.  Chrome is excellent. All the fittings are original and are in reuseable condition. 
I do not like rust and rusty parts are always replaced, so a nice saving.  Only new thing is the brake check sticker.  I bought those for the 175, but did not need them.  The 175 has the notice cast into the brake plate.
I think the 175 front wheel had over £200 spent on it to get to that point.

Cost this time. Maybe £2 in paint and materials, plus my time.  Maybe 4 hours total.




Fork seals still not arrived and since the were posted for next day delivery and were due Tuesday, it is obvious they have been lost in the system.  I have informed the vendor of the non delivery and have had no reply, so I ordered genuine ones from elsewhere.
My usual luck will apply and the things will turn up tomorrow..and require returning.

Those forks are really holding the wiring up.  Cannot fit the headlamp shell without them.