skyhawk or realtuned rocksolidengines motor?

[jji7skyline]

I'm stuck choosing between two engines.

The 'real tuned' 70cc from rocksolidengines http://shop.rocksolidengines.com.au...ion=com_virtuemart&Itemid=1&vmcchk=1&Itemid=1

Or the skyhawk gosickem with performance upgrades
http://www.mbbimports.com.au/2-stro...gosick-em-70cc-american-most-populer-brand/64

Also, is the CNS Carb any good?

 

[Dave31]

My experience with the CNC carb is that it works fine, but it takes a lot of fiddling and tuning.

 

[jji7skyline]

The website says the CNC Carb has its adjustment screws sealed to comply with regulations. That's bad right?