Originally Posted by
jnc011994
hi monty, whose rex welch? anyway, question on GXII. Practice run and engine runs good. Idles great. I wanted to put some more low end grunt. Using Losi 2 alum/green 2 comp./gold. So i adjust 1 hour on low speed needle, blip blip blip blip / WOT and engine dies... returning back to its setting 1 hour back, engine runs good. Why is that so?
Thanks,
Rex is 22Racer on here. He mods and repairs engines for a living.
I suspect the way you have your engine tuned, you are going too far in on the bottom end. Do you lean or richen the bottom end when it dies ?
The GXII (like the GX and it's predecessors) has a long tapered low speed needle. This tapered needle sits well inside the receiver jet. If you set it too far in, you can actually completely block off the receiver jet with the taper.
Craig (curacing2) our GO team driver here posted some info on this a few pages back somewhere too.
Race tune generally on the GXII will see the bottom needle screw flush or maybe 1/2 a turn in from flush with the cap. High speed needle the same.
I suggest you go back to flush on both needles, set the idle gap to .7 mm max, and tune from there.
The GXII has mega bottom end, so you shouldn't have a problem getting the performance you want.