I have heard of a random washer falling out and getting lost when cylinder was reconditioned...  the one I remember the machine shop used one of those heated high pressure wash cabinets like a big dishwasher for engine parts. 

I don't remember if it was this forum or the old one...  but someone also thought the washers were missing and added new ones...  a mistake discovered when they either stripped a cylinder nut or noticed there weren't many threads showing on the studs...  can't remember, it was a long time ago.

Ahh--ok, things to be careful of.

In my defense, you can't really see the pressed-in washer.
So I carefully fitted the aluminum bolts and could see that they are in place and secure the cylinder. So the washers seems to be in...

I had the same problem with my Royal Enfield, it was important that they were special aluminum washers which you should not forget. Hence the question.

Royal Enfield-- umm--its 60 years since I worked on my 350 bullet. Where I worked back then we were RE agents but don't think I ever saw one in the shop except mine. I used every new gasket set we had jn stock as I had it in bits almost weekly. It was my first motocross bike but kept throwing me off then jumping on me just to teach me a lesson haha. I Won the war & sold it to my mate.

I imagine an Enfield as a motocross is quite heavy and sluggish, but a nice experience you describe!
I converted my 500 to a chopper and after some optimisation don't really have any technical problems. But I also don't ride very much and certainly more comfortably than you did off-road. Did you have any thermal problems? I also fitted a larger oil pump, as the original one is probably quite small and can cause overheating.
If you are interested, here is a short video of mine
www.instagram.com/p/C9PbpsjIMyL/

I have now reassembled everything and was able to start it for the first time yesterday.
I also replaced the ignition (breaker contact, capacitor, ignition coil) and checked the oil pump for minimum stroke. Also replaced the diaphragm inlet. So I should have replaced all wearing parts as a precaution.
It started on the first try!
Im happy with the new paint, hope it lasts a long time without flaking off.

Here some photos of the final result. PS: After the video, I set the pilot air screw to the factory setting. This made the engine run better
imgur.com/a/Q3r83RS

I have now filled up with 1:100. How long should I take it easy on the engine before I can turn the gas tap properly?
I will retighten the cylinder head as described.

A while back I checked the compression on my CT-1, and with my cheap tester it only came up to around 70 PSI. I knew that probably wasn't accurate, and likely because of the 14" 1/4" ID rubber hose from the spark plug hole to the meter, where the Schrader valve is. From what I understand, some testers have a Schrader valve in the fitting that goes into the spark plug hole, and with those I don't think it would matter as much how long the hose was.

So today I tried an experiment. I cut the hose out leaving about an inch on each fitting, and joined it back together with a 3/16" ID brass barb fitting. A 1/4" barb union would have fit the hose better, but I used hose clamps anyway, and I thought the smaller fitting would reduce the air volume between the spark plug hole and the meter. Well, it worked! With one kick I got over 90 psi, then after about six kicks it leveled out at 110 PSI.

That was with a cold cylinder, so I let it warm up, then tried it again. It actually dropped a little bit, to just over 105 psi, but then my neighbor came over and gave me a push with the bike in second gear, and it went up to 115 PSI. One cool thing about this setup is that it's easy to screw in without removing the tank.

JFY 

imgur.com/a/s8zImAY

Update: I just cut the hoses off a bit more and also shortened the barbs on the union. Now I can get 120 PSI just kicking it cold. I still don't know if that's completely accurate, but it gives me a good baseline, and it sure is better than the 70 PSI I was getting using the full hose!

imgur.com/a/4UgT6eS