Hi Greg,

Thanks for the info. As we mull and speculate, we have fun.

About settling. We are having temps in the 80s and 90s now so that may certainly be a factor. And settling even happens to glow fuel. I had some 60% nitro fuel with 25% castor last year that I ran on my TD .010s and .020s during a "warm spell" in the winter. Temps were just above freezing and yes, the castor was settling out. At anything significantly above freezing, no problem. Never saw this problem with any other fuel at low temps. Going to pop that fuel jug into the freezer to test. Will report.

Actually, the Amsoil percentage was 10%. If I misstated, I'll fix it. But yes, throttling disappeared with the high Amsoil mix. The question is, did that happen due to chemistry or was it that the main needle setting took the idle setting out of range. I didn't have a chance to play with the airbleed setting on this run. Rain and other obligations, just then, forced a shutdown of activity.

The high Amsoil issue is going to be more fully explored with engines that were actually MEANT to be throttled, like the Norvels and others. The PAW is FORCED to be throttled against its wishes, it seems. The point here is that engine design, as much as anything determines how well it can be throttled and the PAW is a poor frame of reference, in my opinion.

More testing fun and reports will follow.

Addendum:

Reduced compression, as in this case, will necessitate the needle to be leaned out by a good measure. This would take the idle mixture lean and the engine quit in just that manner, abruptly and without warning. So, I'm speculating that the idle went overlean and killed the engine.