OK, I have reflected on this some more and have the following thoughts:
First, 25 degrees initial advance and 10 degrees centrifical advance are only 35 total. This is normal and maybe even somewhat low for a performance engine. So your total advance is OK, no issue there. Also if you have a hot (hugh duration) cam, you will not build a lot of cylinder presure at lower rpm. These reasons are why the engine runs well and does not ping.
Second, the Duraspark ignition retards the timing during the starting cycle (for easier starting) and explains why you have no hard starting problems.
The only question it why won't is run when set at 14 degrees initial advance. It should start and run fine until about 3,000 rpm where it only gets another 10 degrees of advance from the centrifical advance for a total of 25 where it should then be way down on power.
Maybe your Duraspark modual is broken and stuck in start (retard) mode. The physical timing would be right, but the electrical signal going thru the Duraspark box would retard the actual spark to the plugs. This might explain it. Try getting a new Duraspark module.
Ed
