Thank you for the response. Yes, I found a leak (just 2 minutes ago) at crank-side bearing seal. I'll replace both sides to start with, then track down / look for other leaks.
All leaks are gone, holds pressure and vacuum,,,, it has new fuel line and filter: Still runs at a slightly high idle for about 30 to 45 seconds before it settles down. I also checked a second 028 for leaks: it also holds pressure and vacuum, and acts exactly the same thing as the first saw. I want to check the port timing before swapping the cylinder head , after this is completed I will post the results: I'm leaning toward this being the nature of the beast.
This isn't a new development. I bought two 028s on ebay, for under 100 each; one was sold a seized, but the compression is soo good, the person who sold it couldn't pull the cord. I replaced the impulse line, and crank seal on the flywheel side. I triple checked for vacuum and pressure leaks, it does not leak, and it runs fine. But it takes about 35 seconds for the idle to settle down a bit (Sorry, I don't have a tach, or i'd post the rpms). The second ebay find does the same thing: I replaced the intake boot, and impulse line, then the oil pump, I put on a new HyWay cylinder and piston (now I'm replacing the inner dust/clutch cover and oil gears since they both got blown to bits, (they were abused when I got it). It also, now, has no leaks, but takes about 35 seconds to settle down. I like your proposal about having excess fuel in the crankcase, that is quite logical. Thanks. I haven't paid any attention to whether or not it runs high idle if it is started warm, without a choke. (I do run them both a little fat, especially the one with the new cylinder and piston).
