If you get left with sticky residue after it come off then get a small pot of cellulose thinneer from halfords and dampen a tissue and wipe off.
As for maintainence,
Just a basic riders check:
Tyres
Lights
Chain
Brakes,
More or less everything else should be covered by your service.
Just a quick tought.
Loosen the yoke pinch bolts and rotate the fork legs 180 degrees, if they are bending when stopping then it may help to se if the problem goes away.
It's a dodge repair really but quick as you like and saves a strip down.
The strip is actually a fairly easy job. the hassle comes when you end up with a pot of waste oil and no where to put it.
there's a bolt at the very bottom of the forks, this holds it all in place togeter with the screw/circlip at the very top.
Too much petrol is usually a symptom of an incorrct float height or sticky/faulty needle.
I think your suffering enough Ged, you must be pulling your hair out!
Your fork leg will need to have the correct spacing, I think it needs to be 83mm to use the twin pot.
I don't know your bikes' particulars but I have a YPVS that use the 2 potters.
Sticky forks sound a bit unusual,
You could have a bent fork leg,
saggy springs
terrible oil,
you may have a rebound damper spring gone.
Alas, it's a csae of strip down to check.
Few of things,
Is the choke on?
Is the 'idle jet' clean, are you positive the carb was clean.
Is the carb set up for idle, right number of turns on the airscrew etc...
I'm not surprised that you've been having a hard time. It must be pretty hush hush so far. If Yamaha haven't been on the course yet there can't be many people who do know.
At the risk of upsettting existing members;
www.visordown.com
they have a wealth of knowledge.
www.motorcyclenews.com/
might have discussed this somewhere.
Hmmm...
Just having a think.
Why should it run better when warm as the fuel in on the cold side of the engine. The only thing that comes to mind are the bores, rings and valves which might expand and seal better, have you thought of a compression test?
Nice, well done.
It's always a worry having a bike where people can see it. Twoc'ing is all good and well for the louts but they don't appreciate the long term saving or bank loan that usually goes with owning.
try to hold of for a while and then you'll sleep better too.