Originally Posted by tim turbo
I have a BikeBerry black 66cc motor I bought three years ago, and it has 10mm nuts on the head. So I don't think head bolt size is a very good indicater of displacement. The motor looks like a 66cc, with the square head, my 48cc has a some what smaller head that is more rounded looking. Just my 2 bits on the subject!
OK, so maybe the consensus is that the motor he has is older (manufactured a while ago) rather than being a 48cc (since the head bolts are 10mm). I just started this hobby this spring, and all I have seen are newer motors manufactured in 2010/2011, they all seem to have larger head studs than exhaust/intake studs.