restarting diesel engine

Starting my diesel the first time of the day is no problem any more, but the second time is. I cannot find out what to do with the compression. PAW suggests to increase compression from the position it last run best in for a cold re-start, and a decrease in compression for a hot re-start. I fly CL stunt trainers. I do my flight, land, bring the plane back to the starting point, clean the lines and the plane, fill the tank and then want to start again. This procedure takes 3-4 minutes. None of my diesels start immediately in the same fuel/compression setting at such a moment, so I start fiddeling and it sometimes takes a quarter before I get it to run again. So after such a pause of three minutes, what am I trying to accomplish? A cold or a hot restart? How long does it take an engine to become 'cold' again?

A warm restart, maybe. Most diesels will need more compression to start after the cool down period you mention. I have only two that will restart cold without changing from the running setting: an ED Super Racer and an Oliver Tiger replica. But they need to be choked a couple of times, and primed in the exhaust with the piston up. Then they will start after several flips and warm up and run fine. The more you run your engines the better they will start and run. Try a heavier choke and prime (wear a glove) and if that doesn't work after say 6 flips, start increasing the compression until the engine fires, then back the compression off to the running setting. Leave the needle valve alone.

I have 2 paw's 2.5, single BB and 2 BB and a CS oliver tiger replica. All 3 will restart, finish a flight pick up the plane and walk back to the launcher, with a simple choke and flip. They have to re warmup to smooth out but I have no problem with the restart. Possible to little ether in your fuel??

I will try adding some more ether, though I use a 'sports' blend that already has more ether in it than competetion blends which if I'm correct tend to have as much petroleum in it as possible (petroleum is the Dutch word for it, you will know what I mean. I know it's called different in English, but I can't remember it at the moment). I glad for you that your engines restart so soon. I am told as well that as diesels become better 'worn in' the are starting to start better as wel. Still it makes me wonder why PAW would add this advise of re-adjusting the compression in their usermanual. Also I have seen some people in the UK busy giving children their first flight with a trainer with probably something like a 1cc diesel. The plane landed, was picked up, filled, turn on the compressionsrew, strat in one flip, compression set back and launch, time and time again. That's what I would like to accomplish. Unluckily they were much too busy for me to ask what they were doing and my time there was limited. PP