I crashed a plane that had a Tower 75 in it.

After rebuilding, I tried starting it tonight and it sputtered and quit. Did that a few times so I checked the glow plug. Checked out RED...???

After about 5 more failures, I put the plug that came with the engine back in. It ran perfectly.

Anybody have any insight into the plug Tower ships with the engines? Seemed to make all the difference...and I want to buy more.