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I have a Raptor 30 v2 w/ a TT39 ring. I run 20 % nitro / all synthetic oil and am currently using an A3 plug. I've been having real trouble lately getting good 3D power out of it. I run the engine at between 215F and 240F degrees. Yet it runs too rich and is indicated so by the fact that the glow plug is turning dark on the bottom. Does this indicate late ignition? Do I need a hotter plug i.e. #8. Maybe I need to use a cold plug for a leaner application i.e. O.S. R5. Any suggestions.[img]i/expressions/face-icon-small-confused.gif[/img]<font color=white style="background-color: 3E3E3E;">Text</font ft>

Try running a hotter plug. That's always solved my sporadic car engine problems. OS8's are good plugs, and so are Mccoy 59's. Both run pretty hot