Don't flood the engine either when using a drill. They have more power than the rotostart and can strip out the starter gears or snap off the starter pin inside the engine.
So i replaced the one way tried to start it with a drill and used my glo plug still nothing so I'm running out of ideas and hope also nh doesn't really have any nitro rc shops in the seacoast
Make sure you are purging the fuel to the engine. Sometimes the motors just need to warm up. I have hadtimes where it took a few minutes to get my truck to start..