Hopping up the HPX 4x4 gas?

[ssrob]

So what's the trick? Where's the guides? I want it to go faster.

Also, what's them black knobs on top of the carb?

 

[TOMMYHPX4X4]

don't know i always wondered the same thing about them black nobs.although i do notice that mine are not pointed in the same direction and one of the plugs have black soot all the time on it (the rear cylinder).