Matt
If it makes you feel any better.. You are not alone with engine woos...
DA170 on re3 pipes:
"I went out to practice with the Suk on Sunday and 3 minutes into the first flight the motor stopped on a down line, it did not feel right when turning it over by hand and when I pulled the motor yesterday and looking in the exhaust port I see the piston moving laterally in the cylinder about a 1 mm when slowly turning it over-it looks like a bearing is toast and maybe a ring is broke so off to DA it goes today. " The engine had 5-flights...
This wasn't my engine so I can' comment much more ..

Did you say, you had tried running the engine with other ignitions??
I guess the starter is the way to go with this one....

One good thing out of this is that when using a starter...you don't run the risk of wrecking the cowl with miss hits from you hand or chicken stick...
Perhaps though, when you get into the 20" size props there isn't a risk of this as much as when using smaller props in the 15-18" range!....