Love it. 
Of course we all secretly think we are at the top of our game.  We have the diplomas hanging from the walls.
we have the experience.
We have reams and reams of book learning.
We talk elequently of adiabatic combustion and its nemesis, entropy.
But of course we are all chimps deep down, and when we forget that, fate will give us a stark reminder..


Start you bastard....what the feck is wrong with you now???)

Well it starts.  Not as crisply as I would have liked, but it runs.  It sputtered and died on the first few kicks, gradually getting a little better each time.  By maybe the 5th or 6th kick she was running.  After that, she is first kick reliable.

I don't suppose that is too bad considering the winter temps.

We turn to the headlamp.  Does a conventional 5 and 3/4" car sealed beam fit in the headlight rim?

 Reason I ask is because a retailer is selling 5 3/4" sealed beam direct replacements intended for classic cars and comes fitted with a 6v  Halogen bulb for a 3 pin H4 type connector.  I guess this means I do not have to tamper with the original connector and the light will be brighter.

Alternatively I can just buy an aftermarket reflector and american prefocus 35/35 bulb holder suitable for DT175MX.  I know the headlamp bucket is the same on both bikes but I will have to rewire the connector.
Obviously the sealed beam replacement is the preferred option.  Monetarily, there is very little difference between the two options.

I have a new 300 x 16 Kenda K262 rear tyre and new tube coming from Germany.  It was oddly cheaper to buy from a German retailer and pay for shipping than it was to spend more time trying to source one in the UK.

Depending on the state of my hand, I may wait till the holidays to fit it.  That makes the rear end complete.

I have ordered the front tyre and tube also, along with new rim tapes front and rear.  I made the decision to swap out the wheelbearings while I have the wheel out.  Nothing wrong with the originals, but no point having one set of old bearings when every other one is new.

That rear fender is still taunting me...

Outstanding items are the tyres, headlamp as mentioned, exhaust outlet ( still available from yamaha), a set of indicators, the annoying fender, a pair of  mirrors and she is pretty much complete.  The tailamp is ready to bolt straight back on the fender.


 

I came across a historic thread on here detailing the original sealed beam bulb number as 4020.
I looked on ebay and found a UK supplier for that unit selling them for £22 shipped to the door.

I did not realise they were readily available.  Even has " motorcycle" embossed on the glass like the original.  Think.the make is General Electric from what I can see of a makers logo.  Seems like a no brainer to keep the bike original.

Hard to make out but the manufacture logo in the centre looks like GE.


 

Well.  Since I hurt my hand, apart from attending to one handed stuff, I have been pretty stuffed where work on the bike goes.
Saw the quack yesterday and he advises I may be good for light duties next week.  Light duties in my job? Yeah ok.

Anyway, I can use a screwdriver without too much discomfort now, saw I thought I would have half an hour on the bike.

The lay up has meant I have had a lot of time to stare at it and ponder.... Why does it start once OK, run fine, then refuse to run more than a second the next time.

One of those problems that strongly pointed to a malfunction on any of the systems.  Fuel, air, spark or compression.

Carb was cleaned, all passageways and jets I could get into scrubbed and it had a half hour in the ultrasound bath, then everything checked by blowing through.
Ignition system is all new quality aftermarket with a fat spark.
I know know it is not an issue with the plug after trying 3 or 4 with the same result.
Dropping fuel into the carb or cylinder resulted in a strong start.
I strongly suspected a weak condition from cold.  I knew the pilot jet was not plugged because it runs ok when warmed up a few seconds.
This meant the enrichment circuit.  After stripping the plunger out and blowing down the plunger drilling  into the float bowl, it started on second kick and picked up strongly within seconds . Yippee
Time after and subsequently attempts since, it once again became difficult to start.  Why!

Now able to at least hold a screwdriver in one hand and steady a part in the other, I could look a bit deeper.

I think God loves a tryer because by jove, I think I found the answer.

Strongly suspecting the float level because I do not have reliable info , I thought it may be too low causing the weakness.  I never head of it affecting the starter circuit though, but everything else checked out.  I had already ensured the starter circuit drillings to the plunger was clear.

I removed the carb with a bit of difficulty, very little room around the carb area to get in on the 100.  Airbox has to be removed because it surrounds the carb on one side, and exhaust is very close on the other.  To remove the airbox, the chainguard has to come off.  A bit more work than my hand needed, but best foot forward.

I pulled off the floatbowl and looked down the starter jet.  Nothing.  I blew down it.  Nothing blocked.  I poked a torch nozzle cleaner into the starter jet tube intake.  It was clear.  Hmm why start, then cut after a second..

Ping. If there was some loose debris or fluff in there, in between the tiny intake to the tube and the bottom of the tiny jet, it may allow fuel into the tube, and on kicking the bike over, float up to the underside of the jet, partially blocking it.
The bike starts, quickly uses the fuel above the jet and cuts.

To cut a long story short, I swapped the float bowl from my other carb to try.

Tank back on, fuel on.  Ignition on.  First kick.  Light off and an extremely strong start indeed. Better than it has ever done.

I will retest tomorrw to see if I cured it or not, then button everything back up.


 

Well I gave it just over an hour to cool down to ambient again after its previous 10 second run.

Airbox back on, tank on and try again.  Once again,  first kick and an extremely confident start.  I will button everything else up tomorrow.

I think what probably happened is there was scale inside the starter jet tube between the jet and the inlet.  The ultrasound cleaner likely knocked a flake loose off the wall.  This flake was too big to escape from either end and was just floating loosely around and kept getting dragged into the starter jet.

All the other symptoms were incidental, just to add a bit of confusion to the proceedings.

The tormentor twins.  Both have presented me with some very puzzling challenges during their refurbishments.  Stuff that seemed straightforward at first that ended with some very surprising solutions.  Camera lens fogging due to how cold it is in there.


Just waiting for the headlamp and tyres to arrive.  The inner tubes are safely here as is one of the rim tapes.  The second rim tape arrived in not so peaceful a manner.
Unfortunately as I came out of the conservatory after the first start, feelling smug, I was made aware of the fact that the postie had called and dropped the post on the doormat, by way of the wolfhound pup trotting over and happily presenting me with a brand new, but very chewed up rim tape.
Further investigation revealed a torn up credit card bill and a parcel containing the wire W clips for retaining the headlamp in place with the end almost ripped out.

Give me strength....


​​​​

Back into the conservatory this morning.  

carpet slipper changed for trainer - check.

Fuel on - check.

Choke out - check.

Ignition on - check.

Kick.

Cockroach? :-)

Mexican Fiesta… it started, ran like a champ… so celebrating with tequila !!
I’m hoping..
Sneezles61

Yup I hired the mariarchi band because it is now a one kick wonder.

Tyres have arrived safely, but hurty paw means I dare not try change them yet. I see a lot of cursing and sweaty hair this xmas...


I finished ordering all of the outstanding parts and unless I hit any more serious snags,, my initial deadline of a Xmas completion will be met.

Then I board another vexing merry go round with the holy piston. 

Ordered a brand new RT100 exhaust baffle in the end. Someone in the UK was offering a complete rear silencer with baffle for just shy of £70 inc shipping. Silencer hanging bracket was broken off.

New baffle from Fowlers was £79. For £9, it was not worth risking finding the locating thread on the baffle stripped and it welded into the silencer.

A bloke in the US has a used baffle for DT100 and is asking £98 plus £30 shipping. 
Jog on matey.

One outstanding part I cannot find is the little plastic thumb toggle and screw for the indicator switch.  I will probably buy a used switch to rob it from. Lots of yamahas from the 70s and 80s had the same toggle.  Really vexing thing is that the 175 came with a cracked left hand switch complete with switch toggles.  At the end of the resto, I threw all the unserviceable bits in the bin.




So.. i can now add up all the costs.


Total costs.

Bike cost £900.
Transporting the bike home £0.00.  A mate from work helped me pick it up in his works van.
Parts and consumables cost £991.53p.
I will add a fudge factor of £100 for any unforseen future costs such as faulty flasher can ect and cost of VJMC age certification for registering it for the road.

Estimated budget was £900 so not too far out.

So a restored, basically mechanically as new DT100 just cost me £1991.53p which is probably around its actual retail value.