Re: Getting all 3 Horse Power out of your GT-5 Sky? (tear down)
I think the problem could be the exhaust to some degree, but the ignition timing probably is a bigger problem. From what I've seen, the stock cdi box has no provision to adjust the timing. It's just constant at whatever advance it has to start with. Manic Mechanic said it's about 6 degrees BTDC, and needs to be more like 12 degrees BTDC for best performance.
He claims the stock magneto rotors all vary slightly in timing, because of manufacturing tolerance, but none of then offer enough advance. This is the major reason one identical motor makes more power than another, so he says.
I've ordered one of his adjustable rotors to experment with, and it should come today. I'll let you know what I find after I've had a chance to play with it.