Brian,
I just did.
Please read post #7 in that thread:
ORIGINAL: DarZeelon
Jimmy,
In a tapered-bore engine, you would not want it to run at a four-cycle, rich setting, for the duration on the break-in.
Please read the thread carefully.
So the fact that you cannot make to rich enough to four-cycle, is not very important.
You must, however, be able to richen it enough to spin about 500 RPM less than peak.
If it is not very rich and four-cycling, you do not need to keep the glow driver on, for it to run.
The Thunder Tiger .46 PRO is a $75 ABN engine, which is much less likely than an OS.46FX, to peel its nickel. But if this should happen, a new piston+sleeve will cost $68 - 90% of the engine's total price, not including shipping...
Welcome to RC Universe.
As you lean the mixture; breaking from a definite four-cycle to a clean two-cycle mode, the engine will immediately gain 1,500-2,000 RPM.
If you lean it further to peak it, you will only gain about 500 RPM more, before the mixture becomes too lean.
This is typical in sport engines.
Some very high performance engines that cannot be made to four-cycle cleanly (Bob Brassell says most Jett engines will not four-cycle), can be made to run at two-cycle at all RPM levels. So they can be slowed more by enriching the mixture.
Furthermore, Bob wrote that the 60 second very rich initial run, in the Jett web site break-in procedure, is not a four-cycling run, but a wet, unsteady two-cycle.