Most of the folks that have this type of problem are using a glow plug ignitor set up that provides too much voltage to the glow plug. Or, they are using a really hot glow plug. Increasing nitro content may also aggravate the situation.

As Asmund has suggested. Choke the engines and then flip them several times without the glow plug booster power applied. Connect the booster leads. Now flip the prop backwards so that it bounces off of compression. That should start your engine in the proper direction.

Or, if your voltage is adjustable, lower it a bit and flip through compression normally.


Ed Cregger