Bear in mind I've only built the Jan Ridders flamelicker so I'm no expert. The thing I notice is your flame looks quite yellow/orange in the video, what fuel are you using? I use ~95% alcohol and the flame has more blue in it, so is likely a bit hotter than yours.
As for the timing, some air has to be expelled from the port at the top of the stroke to get rid of exhaust gases so I wouldn't be concerned about that. If you close the valve before BDC to get 'extra' vacuum, that power has to come from somewhere and you'll be robbing your engine of full power.
How much preheating did you before the video? If the cylinder is stainless it might take a minute or two to heat up enough for the engine to run. It's certainly making all the right noises. Check your fuel, preheat the cylinder and have another go maybe? Good luck!
Fuel is from a can of Klean Strip denatured alcohol from the hardware store. The company website says about 50/50 ethanol and methanol mix. Should be about the same as yours. As for the color of the flame, possibly something dripped on the wick from another project a while ago. Or the wick burning itself. The wick is black, like it has been burning.
In that video, I didn't preheat the cylinder, but for most of the time I was working, I heated it 30 seconds or so in the flame, enough to get it too hot to touch. I had been messing with the engine for a long time and then had to break for an hour to recharge my camera's battery. Since I was just there to take the video, I just sat down to spin it. I mostly wanted folks to hear the sounds of the air compressing or escaping
The alcohol lamp was always supposed to be temporary. Virtually every video has a custom alcohol lamp and every video has the guy fooling with the placement to get it exactly in the right spot. Since the Duclos plans have a lamp made from a door knob that's permanently mounted, I thought I'd try something I already had and not mount make a mount for it until I found where it needs to go. The problem was I never pulled the lamp up to the cylinder until yesterday. That's when I saw it's much too big.
Looks like another week or so. I started cutting metal around the end of February, and didn't start this thread until May, another few weeks doesn't matter.
Meanwhile, I need to find some .015 spring wire to wind a spring. I think I mess with the spring before I mess with the timing. I said I started with a spring from around the house with .015 wire and stretched it out, then went to a bigger wire spring and cut it off. After the second time I cut it back it looks like this:
That gap isn't that big. Rough guess is 1/16". But it doesn't press the cam roller onto the cam. The slightly too long spring is less bad than this, but it needs to be replaced.
Somewhere in there, I make an alcohol lamp.
