Well last night whilst I was asleep I must have had a visit from the M20 fairy. How do I know? Well last night I left the shed with that love hate relationship you have with you bike over time, you know, put your riding gear on kick the living sh*t out of it wont start, strip off try again and away it goes. Stop at the servo, top her up and yep wont go, quick push down the street and off you go thinking I hate you.........then the ride just does something to you suddenly hate turns to love. Like all good things the ride comes to an end. Quick wipe down and maybe I will start her one more time, just so I can listen to that thump, thump,thump one more time...... you got it bast*rd wont start. So inside you go back hating the bloody stubborn thing.
Well over the last few weeks I have read nearly every thread on this forum, written a few, asked some questions, received very mixed replies, got some great advise and learnt that you need to stop, take a sip of scotch, maybe two and start from the beginning. My bike had been sitting for several years before I picked it up so anything could be wrong. I started with set Tappets, clean points, set timming, change plug, change oils, check oil flow,grease everything, check wheel bearings, adjust a few bits, strip the carby. One would think that with everything right maybe it should start easier. Wrong....I found the pickup on the mag was cracked so replaced it, still no better. Plug lead was looking a little ordinary so that got changed, engine was cold so I thought I would check head bolt tensions, went down a little, finish the scotch and back inside to read more threads..... went down the shed tonight, fuel on, retard on little tickle, wide open throttle, decomp on, three quick ones, pick up comp stroke, here we go I thought and bang it fired up....shock set in....??? Couple of laps around the block, turn her off, memory bank remembers advise from forum members, similar start procedure as earlier but with a bit more throttle, first kick.... more shock...Scotch time... six starts all easy in a row. So obviously the M20 fairy must have been and done its magic....
Thanks guys for sharing your experience, now to enjoy the love of riding these old machines
Cheers
Glad you're getting the hang of it 
Since I've had my mag rewound on my 16H I would bet anyone my bike will start first kick. I never think it won't start.
I've been having starting problems with my Manx, and when you're bumping it up and down the road the novelty soon wears off. There's a nice blue spark on the HT lead, but not when you put a plug on the end. So enough's enough and I've just dropped the mag off at my local rewinders and he's confirmed it's down on power. How many months of messing about has that caused...! 
email (option): horror@blueyonder.co.uk
Funny things magnetos.
I fitted a NOS Lucas to my '38 bike back in the 1970's, I have ridden that bike to the south of France and the borders of Spain; in all weathers, snow torrential rain, heat and its never let me down or failed to start the bike. In fact it's never had the points changed.
I use Lodge platinum tip plugs which never seem to wear out much, but most of all that magneto has never had a suppresssed plug cap at the end of its lead. That or a resistor plug.
I reckon they are the cause of most mag failures whether fitted now or in the past at some time.
In fact, DH Day of Swindon, the guy who overhauled the magneto on another, older bike stated right off that if you fitted a suppressed plug cap it would invalidate the guarantee he gave.
Of course sods law now decrees the damn bike now won't start tomorrow
I always have my mags reconditioned when I rebuild a bike or buy one and am unsure of when the mag was last overhauled.
I generally fit new carburettors and keep the rest of the bike 'up to scratch' and have no real problems...
There are plenty of forum members who can confirm that over the last 15-20 years at multiple 'military' events and on many Normandy tours my bikes always start and don't break down...
It is a 'false economy' to try and run worn out equipment..it will always cause problems at some point...Ian
email (option): ian@wright52.plus.com