Yes it is a side port model.. at first I had thought it was a rotary valve (reed) model but I was wrong....
Just to clear something up for you mate, rotary valve is NOT another term for a reed valve engine.
A reed valve engine uses a metal 'reed' to create a one way valve on the crancase, through wich fuel/air mix is drawn when the crancase forms a vacuume as the piston ascends the cylinder.
A rotary valve engine uses a rotating valve (as FAST has described above) of one form or another to control the flow of fuel air mix into the crank case. the position of the valve is controled by the position of the crank, and is fixed, unlike a reed valve (ie, if you turn an engine till a reed valve opens then hold it, the valve will close over once the vaccume inside has gone, however a rotary valve will remain open)
