Okay. I think the original was an OS #8. Right now I am running 10% fuel. I was running Cool Power 15% and plan to go back to that when I buy fuel again. I need to order a new glow plug so I wanted to make sure which to use....next question and probably a dumb one. If I put my glow starter on the plug with it removed from the engine, should it heat up and glow constantly? I started my plane this evening but when I tried to start it the next couple of times it wouldn't. I pulled the plug and connected it and it glowed for a split second and stopped. It did that a few times. I got it started again but had the same problem after that run. I think my battery powered Tower glow starter may be acting up. May be time to order a new one. Speaking of that, is there a better choice for the glow starter or is one basically as good as the other?