Great result on the engine run.
For the spark test and paint bit, I have a length of wire, with croc clips on, 1 clips on the plug and the other to anywhere on the bike so I can have the spark plug hanging to aid seeing it rather than tucked in the head.

As Derek would say glad you got the sparkalators fixed and some fuel in the fuel maker happenor Great news 
​​​ ​​​    

Yes and I did not get a carpet slipper launching into low earth orbit.  This time I remembered to put a pair of trainers on the ends of my Kick O Matic 5000s.

Tomorrow will be tidying and clipping up the wiring, fitting the airbox again, fitting the tank properly, fitting a new lock tab under the engine sprocket before fitting the sprocket cover,  the chainguard and tensioning the chain.  I may even get around to fitting the rear foot brake lever and shaft.
I may then be able to take her for a spin down the farm track at the bottom of the garden.

Wiring routed and clipped.  Airbox refitted, chainguard refitted, chain tensioned, gear lever fitted, generator and sprocket covers back on.
​​​​​​Tank back on.  Disappointngly, there is no room between fuel tap and carb to fit an inline filter.  I ordered the smallest paper centered one I could find, but sadly no room even for that.

Set carb airscrew to.2 turns out as per spec, but it would not run.  It would fire and run for a second or so before cutting out.
Turned it in by a half turn and it runs like a champ.

Checked clutch action.  Just fine and even neutral is easy to find once the engine warmed up. A bit recalcitrant until then.
I suspect when the frictions bed in, it will be fine.

Had it idling for around half an hour had did a few more tests.

Horn does not work.  Not looked into it yet.  I have AC voltage up to the headlamp terminals and the instrument lights work.

Thats about it for now. Another requires my attention.
 Need to fire up the VFR and get her thoroughly warmed up.  They are famously warm blooded and hate cold weather.  The need to keep fresh fuel in the carbs is critical.  Once the fuel starts losing freshness, you are in a world of pain.  The cold starting circuit is extremely lean and is barely adequate even if run daily in cold weather.
She will fire on one, number two will chime in and allow it to run without starter assistance.
It can be a couple of minutes until three and four decide to put in an appearance.  Touch the throttle or choke at all until then at your peril.


Instrument illumination lights up, we have main beam lit and the low oil light goes out when in gear as it should.


 

Well.  The bike continues to make a Chimpanzee out of me.

Got the kickstart blasted, painted and refitted during the week, put the oil pump cover back on and gave it a kick over.

Conservatory temp around minus 1c.  It fired and ran for a second, then cut.  Kick, kick, it fired for a second, then cut.
Rinse and repeat for five minutes before abandoning the bike to its freezing cold fate.

Time for a ponder.  It ran fine for over half an hour last time it ran....  All I have done is fit a cover and a kickstart.  The kickstart was fitted previously and has no bearing on the issue.  The oil pump cover is not an issue...

What has gone wrong....?

​​​​​​Ponder 1.  It is getting fuel but losing spark.  But new plug, points and condenser fitted.  Timed up.  Running just fine with no hint of a problem before.

Ponder 2.  It has spark but is not getting fuel. A check of the plug showed wet with fuel.

So number 1.  I fitted the rotor and tightened it with the tools I had available at the time.  My home tools are a motley collection of old cast offs and bargain basket buys. 
I have tools valued in the tens of thousands of pounds at work and this makes for little enthusiasm for buying good tools for home use.  They are completely inadequate for anything but the simplest tasks which is why many of the tasks are done at work during lunchtime.

So has the rotor come loose and sheared the crank key?  It would account for the symptoms.
I finally remembered to bring home my sheave holder and removed the rotor.  Nut was tight and key intact.
At least with the correct tools, now I KNOW the rotor is fitted correctly.  Points were opening and closing as they should.

I dried off the plug with a blowtorch and refitted it, managing to leave a shiny smooth spot on my fingertips as I removed my fingerprints on the getting ever hotter ceramic as I did so.  Great.

Kick.  Start, run for a second, die.  Buggerynation.

Carb?  With no reliable source of float height info, I just made sure the float arms were straight.  Was the starter circuit not dipping into the fuel?  Just as I was contemplating pulling the carb, I spied a brand new plug, loosely screwed into the head of the 175 to keep moisture out until.I replace the piston.

It can't be the plug because it is brand new.  However, it is only a couple of seconds to try.

Fitted the new plug loosely and off she popped on the second kick.  Feck it, faulty plug.  It is not the first of the batch I bought.  I reckon three out of five used failed.  That is in around 200 miles.

I buy my plugs from reputable places like amazon, but there are a lot of chinese knockoffs out there.  I am viewing this packet of plugs I have with considerable suspicion now.  If they are knockoffs, could they have contributed to my 175 demise?

I will refrain from commenting on what I would like to do to chinese knockoff artists with no regard to the end user.  It would not be pleasant reading.

I'd junk the lot of them, TK, and, if you can, buy from your local dealer, or maybe somewhere like Fowlers.

It sure seems NGK is getting the worst of it from those counterfeiters… I haven’t heard about the other brands…. yet.
Sneezles61

If you contact NGK they can help identify if the plugs are counterfeit. 

I've said this before, but going back decades I learned to never start a race with a brand new NGK plug.  I used to "pre-run" my NGK plugs after having roughly 10% of new ones fail after or during the first heat cycle.  I don't think these were counterfeits back then as they were bought from dealers but who knows.  (Champion plugs were even worse at failing )

I was advised to try Autolite...  I did and, knock wood, have had nothing but exceptional reliability.  I can't remember ever having an Autolite fail. I have nothing against NGK and haven't had one fail in recent years like I had so much trouble with in the late 80's/early 90's...  but I still run Autolite and since NGK has phased out non-resistor plugs and has had so much trouble with counterfeits, Autolite is what I buy today.



 

"and since NGK has phased out non-resistor plugs and has had so much trouble with counterfeits, Autolite is what I buy today."

I wonder if this is only in the US, as my local dealer looked at me like I was a numpty when I suggested this to her!   They had no problem ordering in new ones for me.

Just ordered a couple of Denso W24es-u plugs to try. I have no faith in those NGKs anymore.

Happily, same plug in both DTs.

Went to try the 100 again.  Seems the new plug has gone the same way as the previous one.  One easy start and warm up to operating temp run, allow to go cold, then the same 1 second run shennanigans.

We have air.  We have fuel.  We have spark and fire with brand shiny new plug.  We have intermittent or no spark with a heat cycled plug....